1 Known Problems with GNU Emacs
3 Copyright (C) 1987, 1988, 1989, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
5 Free Software Foundation, Inc.
6 See the end of the file for license conditions.
9 This file describes various problems that have been encountered
10 in compiling, installing and running GNU Emacs. Try doing C-c C-t
11 and browsing through the outline headers. (See C-h m for help on
12 Outline mode.) Information about systems that are no longer supported,
13 and old Emacs releases, has been removed. Consult older versions of
14 this file if you are interested in that information.
16 * Mule-UCS doesn't work in Emacs 23.
18 It's completely redundant now, as far as we know.
20 * Emacs startup failures
22 ** Emacs fails to start, complaining about missing fonts.
24 A typical error message might be something like
26 No fonts match `-*-fixed-medium-r-*--6-*-*-*-*-*-iso8859-1'
28 This happens because some X resource specifies a bad font family for
29 Emacs to use. The possible places where this specification might be
32 - in your ~/.Xdefaults file
34 - client-side X resource file, such as ~/Emacs or
35 /usr/X11R6/lib/app-defaults/Emacs or
36 /usr/X11R6/lib/X11/app-defaults/Emacs
38 One of these files might have bad or malformed specification of a
39 fontset that Emacs should use. To fix the problem, you need to find
40 the problematic line(s) and correct them.
42 ** Emacs aborts while starting up, only when run without X.
44 This problem often results from compiling Emacs with GCC when GCC was
45 installed incorrectly. The usual error in installing GCC is to
46 specify --includedir=/usr/include. Installation of GCC makes
47 corrected copies of the system header files. GCC is supposed to use
48 the corrected copies in preference to the original system headers.
49 Specifying --includedir=/usr/include causes the original system header
50 files to be used. On some systems, the definition of ioctl in the
51 original system header files is invalid for ANSI C and causes Emacs
54 The fix is to reinstall GCC, and this time do not specify --includedir
55 when you configure it. Then recompile Emacs. Specifying --includedir
56 is appropriate only in very special cases and it should *never* be the
57 same directory where system header files are kept.
59 ** Emacs does not start, complaining that it cannot open termcap database file.
61 If your system uses Terminfo rather than termcap (most modern
62 systems do), this could happen if the proper version of
63 ncurses is not visible to the Emacs configure script (i.e. it
64 cannot be found along the usual path the linker looks for
65 libraries). It can happen because your version of ncurses is
66 obsolete, or is available only in form of binaries.
68 The solution is to install an up-to-date version of ncurses in
69 the developer's form (header files, static libraries and
70 symbolic links); in some GNU/Linux distributions (e.g. Debian)
71 it constitutes a separate package.
73 ** Emacs 20 and later fails to load Lisp files at startup.
75 The typical error message might be like this:
77 "Cannot open load file: fontset"
79 This could happen if you compress the file lisp/subdirs.el. That file
80 tells Emacs what are the directories where it should look for Lisp
81 files. Emacs cannot work with subdirs.el compressed, since the
82 Auto-compress mode it needs for this will not be loaded until later,
83 when your .emacs file is processed. (The package `fontset.el' is
84 required to set up fonts used to display text on window systems, and
85 it's loaded very early in the startup procedure.)
87 Similarly, any other .el file for which there's no corresponding .elc
88 file could fail to load if it is compressed.
90 The solution is to uncompress all .el files which don't have a .elc
93 Another possible reason for such failures is stale *.elc files
94 lurking somewhere on your load-path -- see the next section.
96 ** Emacs prints an error at startup after upgrading from an earlier version.
98 An example of such an error is:
100 x-complement-fontset-spec: "Wrong type argument: stringp, nil"
102 This can be another symptom of stale *.elc files in your load-path.
103 The following command will print any duplicate Lisp files that are
104 present in load-path:
106 emacs -q -batch -f list-load-path-shadows
108 If this command prints any file names, some of these files are stale,
109 and should be deleted or their directories removed from your
112 ** With X11R6.4, public-patch-3, Emacs crashes at startup.
114 Reportedly this patch in X fixes the problem.
116 --- xc/lib/X11/imInt.c~ Wed Jun 30 13:31:56 1999
117 +++ xc/lib/X11/imInt.c Thu Jul 1 15:10:27 1999
119 -/* $TOG: imInt.c /main/5 1998/05/30 21:11:16 kaleb $ */
120 +/* $TOG: imInt.c /main/5 1998/05/30 21:11:16 kaleb $ */
121 /******************************************************************
123 Copyright 1992, 1993, 1994 by FUJITSU LIMITED
130 + char* begin = NULL;
134 char* ximmodifier = XIMMODIFIER;
137 ret = Xmalloc(end - begin + 2);
139 - (void)strncpy(ret, begin, end - begin + 1);
140 + if (begin != NULL) {
141 + (void)strncpy(ret, begin, end - begin + 1);
145 ret[end - begin + 1] = '\0';
149 ** Emacs crashes on startup after a glibc upgrade.
151 This is caused by a binary incompatible change to the malloc
152 implementation in glibc 2.5.90-22. As a result, Emacs binaries built
153 using prior versions of glibc crash when run under 2.5.90-22.
155 This problem was first seen in pre-release versions of Fedora 7, and
156 may be fixed in the final Fedora 7 release. To stop the crash from
157 happening, first try upgrading to the newest version of glibc; if this
158 does not work, rebuild Emacs with the same version of glibc that you
159 will run it under. For details, see
161 https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=239344
165 ** Emacs crashes when running in a terminal, if compiled with GCC 4.5.0
166 This version of GCC is buggy: see
168 http://debbugs.gnu.org/cgi/bugreport.cgi?bug=6031
169 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43904
171 You can work around this error in gcc-4.5 by omitting sibling call
172 optimization. To do this, configure Emacs with
174 CFLAGS="-g -O2 -fno-optimize-sibling-calls" ./configure
176 ** Emacs crashes in x-popup-dialog.
178 This can happen if the dialog widget cannot find the font it wants to
179 use. You can work around the problem by specifying another font with
180 an X resource--for example, `Emacs.dialog*.font: 9x15' (or any font that
181 happens to exist on your X server).
183 ** Emacs crashes when you use Bibtex mode.
185 This happens if your system puts a small limit on stack size. You can
186 prevent the problem by using a suitable shell command (often `ulimit')
187 to raise the stack size limit before you run Emacs.
189 Patches to raise the stack size limit automatically in `main'
190 (src/emacs.c) on various systems would be greatly appreciated.
192 ** Error message `Symbol's value as variable is void: x', followed by
193 a segmentation fault and core dump.
195 This has been tracked to a bug in tar! People report that tar erroneously
196 added a line like this at the beginning of files of Lisp code:
198 x FILENAME, N bytes, B tape blocks
200 If your tar has this problem, install GNU tar--if you can manage to
203 ** Crashes when displaying GIF images in Emacs built with version
204 libungif-4.1.0 are resolved by using version libungif-4.1.0b1.
205 Configure checks for the correct version, but this problem could occur
206 if a binary built against a shared libungif is run on a system with an
209 ** Emacs aborts inside the function `tparam1'.
211 This can happen if Emacs was built without terminfo support, but the
212 terminal's capabilities use format that is only supported by terminfo.
213 If your system has ncurses installed, this might happen if your
214 version of ncurses is broken; upgrading to a newer version of ncurses
215 and reconfiguring and rebuilding Emacs should solve this.
217 All modern systems support terminfo, so even if ncurses is not the
218 problem, you should look for a way to configure Emacs so that it uses
221 ** Emacs crashes when using some version of the Exceed X server.
223 Upgrading to a newer version of Exceed has been reported to prevent
224 these crashes. You should consider switching to a free X server, such
225 as Xming or Cygwin/X.
227 ** Emacs crashes with SIGSEGV in XtInitializeWidgetClass.
229 It crashes on X, but runs fine when called with option "-nw".
231 This has been observed when Emacs is linked with GNU ld but without passing
232 the -z nocombreloc flag. Emacs normally knows to pass the -z nocombreloc
233 flag when needed, so if you come across a situation where the flag is
234 necessary but missing, please report it via M-x report-emacs-bug.
236 On platforms such as Solaris, you can also work around this problem by
237 configuring your compiler to use the native linker instead of GNU ld.
239 ** Emacs compiled with Gtk+ crashes when closing a display (x-close-connection).
241 This happens because of bugs in Gtk+. Gtk+ 2.10 seems to be OK. See bug
242 http://bugzilla.gnome.org/show_bug.cgi?id=85715.
244 ** Emacs compiled with Gtk+ may loop forever if a display crashes.
246 This is related to the bug above. A scenario for this is when emacs is run
247 as a server, and an X frame is created. If the X server for the frame
248 crashes or exits unexpectedly and an attempt is made to create a new
249 frame on another X display, then a Gtk+ error happens in the emacs
250 server that results in an endless loop. This is not fixed in any known
251 Gtk+ version (2.14.4 being current).
253 * General runtime problems
257 *** Changes made to .el files do not take effect.
259 You may have forgotten to recompile them into .elc files.
260 Then the old .elc files will be loaded, and your changes
261 will not be seen. To fix this, do M-x byte-recompile-directory
262 and specify the directory that contains the Lisp files.
264 Emacs should print a warning when loading a .elc file which is older
265 than the corresponding .el file.
267 *** Watch out for .emacs files and EMACSLOADPATH environment vars.
269 These control the actions of Emacs.
270 ~/.emacs is your Emacs init file.
271 EMACSLOADPATH overrides which directories the function
274 If you observe strange problems, check for these and get rid
275 of them, then try again.
277 *** Using epop3.el package causes Emacs to signal an error.
279 The error message might be something like this:
281 "Lisp nesting exceeds max-lisp-eval-depth"
283 This happens because epop3 redefines the function gethash, which is a
284 built-in primitive beginning with Emacs 21.1. We don't have a patch
285 for epop3 that fixes this, but perhaps a newer version of epop3
288 *** Buffers from `with-output-to-temp-buffer' get set up in Help mode.
290 Changes in Emacs 20.4 to the hooks used by that function cause
291 problems for some packages, specifically BBDB. See the function's
292 documentation for the hooks involved. BBDB 2.00.06 fixes the problem.
294 *** The Hyperbole package causes *Help* buffers not to be displayed in
295 Help mode due to setting `temp-buffer-show-hook' rather than using
296 `add-hook'. Using `(add-hook 'temp-buffer-show-hook
297 'help-mode-maybe)' after loading Hyperbole should fix this.
301 *** "Compose Character" key does strange things when used as a Meta key.
303 If you define one key to serve as both Meta and Compose Character, you
304 will get strange results. In previous Emacs versions, this "worked"
305 in that the key acted as Meta--that's because the older Emacs versions
306 did not try to support Compose Character. Now Emacs tries to do
307 character composition in the standard X way. This means that you
308 must pick one meaning or the other for any given key.
310 You can use both functions (Meta, and Compose Character) if you assign
311 them to two different keys.
313 *** C-z just refreshes the screen instead of suspending Emacs.
315 You are probably using a shell that doesn't support job control, even
316 though the system itself is capable of it. Either use a different shell,
317 or set the variable `cannot-suspend' to a non-nil value.
319 *** With M-x enable-flow-control, you need to type C-\ twice
320 to do incremental search--a single C-\ gets no response.
322 This has been traced to communicating with your machine via kermit,
323 with C-\ as the kermit escape character. One solution is to use
324 another escape character in kermit. One user did
326 set escape-character 17
328 in his .kermrc file, to make C-q the kermit escape character.
330 ** Mailers and other helper programs
332 *** movemail compiled with POP support can't connect to the POP server.
334 Make sure that the `pop' entry in /etc/services, or in the services
335 NIS map if your machine uses NIS, has the same port number as the
336 entry on the POP server. A common error is for the POP server to be
337 listening on port 110, the assigned port for the POP3 protocol, while
338 the client is trying to connect on port 109, the assigned port for the
341 *** RMAIL gets error getting new mail.
343 RMAIL gets new mail from /usr/spool/mail/$USER using a program
344 called `movemail'. This program interlocks with /bin/mail using
345 the protocol defined by /bin/mail.
347 There are two different protocols in general use. One of them uses
348 the `flock' system call. The other involves creating a lock file;
349 `movemail' must be able to write in /usr/spool/mail in order to do
350 this. You control which one is used by defining, or not defining,
351 the macro MAIL_USE_FLOCK in config.h or the m- or s- file it includes.
352 IF YOU DON'T USE THE FORM OF INTERLOCKING THAT IS NORMAL ON YOUR
353 SYSTEM, YOU CAN LOSE MAIL!
355 If your system uses the lock file protocol, and fascist restrictions
356 prevent ordinary users from writing the lock files in /usr/spool/mail,
357 you may need to make `movemail' setgid to a suitable group such as
358 `mail'. To do this, use the following commands (as root) after doing the
364 Installation normally copies movemail from the build directory to an
365 installation directory which is usually under /usr/local/lib. The
366 installed copy of movemail is usually in the directory
367 /usr/local/lib/emacs/VERSION/TARGET. You must change the group and
368 mode of the installed copy; changing the group and mode of the build
369 directory copy is ineffective.
371 *** rcs2log gives you the awk error message "too many fields".
373 This is due to an arbitrary limit in certain versions of awk.
374 The solution is to use gawk (GNU awk).
376 ** Problems with hostname resolution
378 *** Emacs fails to understand most Internet host names, even though
379 the names work properly with other programs on the same system.
380 *** Emacs won't work with X-windows if the value of DISPLAY is HOSTNAME:0.
381 *** Gnus can't make contact with the specified host for nntp.
383 This typically happens on Suns and other systems that use shared
384 libraries. The cause is that the site has installed a version of the
385 shared library which uses a name server--but has not installed a
386 similar version of the unshared library which Emacs uses.
388 The result is that most programs, using the shared library, work with
389 the nameserver, but Emacs does not.
391 The fix is to install an unshared library that corresponds to what you
392 installed in the shared library, and then relink Emacs.
394 If you have already installed the name resolver in the file libresolv.a,
395 then you need to compile Emacs to use that library. The easiest way to
396 do this is to add to config.h a definition of LIBS_SYSTEM, LIBS_MACHINE
397 or LIB_STANDARD which uses -lresolv. Watch out! If you redefine a macro
398 that is already in use in your configuration to supply some other libraries,
399 be careful not to lose the others.
401 Thus, you could start by adding this to config.h:
403 #define LIBS_SYSTEM -lresolv
405 Then if this gives you an error for redefining a macro, and you see that
406 the s- file defines LIBS_SYSTEM as -lfoo -lbar, you could change config.h
409 #define LIBS_SYSTEM -lresolv -lfoo -lbar
411 *** Emacs does not know your host's fully-qualified domain name.
413 For example, (system-name) returns some variation on
414 "localhost.localdomain", rather the name you were expecting.
416 You need to configure your machine with a fully qualified domain name,
417 (i.e. a name with at least one ".") either in /etc/hosts,
418 /etc/hostname, the NIS, or wherever your system calls for specifying
421 If you cannot fix the configuration, you can set the Lisp variable
422 mail-host-address to the value you want.
426 *** Emacs says it has saved a file, but the file does not actually
429 This can happen on certain systems when you are using NFS, if the
430 remote disk is full. It is due to a bug in NFS (or certain NFS
431 implementations), and there is apparently nothing Emacs can do to
432 detect the problem. Emacs checks the failure codes of all the system
433 calls involved in writing a file, including `close'; but in the case
434 where the problem occurs, none of those system calls fails.
436 *** Editing files through RFS gives spurious "file has changed" warnings.
437 It is possible that a change in Emacs 18.37 gets around this problem,
438 but in case not, here is a description of how to fix the RFS bug that
441 There was a serious pair of bugs in the handling of the fsync() system
442 call in the RFS server.
444 The first is that the fsync() call is handled as another name for the
445 close() system call (!!). It appears that fsync() is not used by very
446 many programs; Emacs version 18 does an fsync() before closing files
447 to make sure that the bits are on the disk.
449 This is fixed by the enclosed patch to the RFS server.
451 The second, more serious problem, is that fsync() is treated as a
452 non-blocking system call (i.e., it's implemented as a message that
453 gets sent to the remote system without waiting for a reply). Fsync is
454 a useful tool for building atomic file transactions. Implementing it
455 as a non-blocking RPC call (when the local call blocks until the sync
456 is done) is a bad idea; unfortunately, changing it will break the RFS
457 protocol. No fix was supplied for this problem.
459 (as always, your line numbers may vary)
461 % rcsdiff -c -r1.2 serversyscall.c
462 RCS file: RCS/serversyscall.c,v
463 retrieving revision 1.2
464 diff -c -r1.2 serversyscall.c
465 *** /tmp/,RCSt1003677 Wed Jan 28 15:15:02 1987
466 --- serversyscall.c Wed Jan 28 15:14:48 1987
470 * No return sent for close or fsync!
472 ! if (syscall == RSYS_close || syscall == RSYS_fsync)
473 proc->p_returnval = deallocate_fd(proc, msg->m_args[0]);
478 * No return sent for close or fsync!
480 ! if (syscall == RSYS_close)
481 proc->p_returnval = deallocate_fd(proc, msg->m_args[0]);
485 ** PSGML conflicts with sgml-mode.
487 PSGML package uses the same names of some variables (like keymap)
488 as built-in sgml-mode.el because it was created as a replacement
489 of that package. The conflict will be shown if you load
490 sgml-mode.el before psgml.el. E.g. this could happen if you edit
491 HTML page and then start to work with SGML or XML file. html-mode
492 (from sgml-mode.el) is used for HTML file and loading of psgml.el
493 (for sgml-mode or xml-mode) will cause an error.
497 *** Lines are not updated or new lines are added in the buffer upon commit.
499 When committing files located higher in the hierarchy than the examined
500 directory, some versions of the CVS program return an ambiguous message
501 from which PCL-CVS cannot extract the full location of the committed
502 files. As a result, the corresponding lines in the PCL-CVS buffer are
503 not updated with the new revision of these files, and new lines are
504 added to the top-level directory.
506 This can happen with CVS versions 1.12.8 and 1.12.9. Upgrade to CVS
507 1.12.10 or newer to fix this problem.
509 ** Miscellaneous problems
511 *** Emacs uses 100% of CPU time
513 This is a known problem with some versions of the Semantic package.
514 The solution is to upgrade Semantic to version 2.0pre4 (distributed
515 with CEDET 1.0pre4) or later.
517 *** Self-documentation messages are garbled.
519 This means that the file `etc/DOC-...' doesn't properly correspond
520 with the Emacs executable. Redumping Emacs and then installing the
521 corresponding pair of files should fix the problem.
523 *** Programs running under terminal emulator do not recognize `emacs'
526 The cause of this is a shell startup file that sets the TERMCAP
527 environment variable. The terminal emulator uses that variable to
528 provide the information on the special terminal type that Emacs
531 Rewrite your shell startup file so that it does not change TERMCAP
532 in such a case. You could use the following conditional which sets
533 it only if it is undefined.
535 if ( ! ${?TERMCAP} ) setenv TERMCAP ~/my-termcap-file
537 Or you could set TERMCAP only when you set TERM--which should not
538 happen in a non-login shell.
540 *** In Shell mode, you get a ^M at the end of every line.
542 This happens to people who use tcsh, because it is trying to be too
543 smart. It sees that the Shell uses terminal type `unknown' and turns
544 on the flag to output ^M at the end of each line. You can fix the
545 problem by adding this to your .cshrc file:
548 if ("$EMACS" =~ /*) then
550 stty -icrnl -onlcr -echo susp ^Z
554 *** Emacs startup on GNU/Linux systems (and possibly other systems) is slow.
556 This can happen if the system is misconfigured and Emacs can't get the
557 full qualified domain name, FQDN. You should have your FQDN in the
558 /etc/hosts file, something like this:
561 129.187.137.82 nuc04.t30.physik.tu-muenchen.de nuc04
563 The way to set this up may vary on non-GNU systems.
565 *** Attempting to visit remote files via ange-ftp fails.
567 If the error message is "ange-ftp-file-modtime: Specified time is not
568 representable", then this could happen when `lukemftp' is used as the
569 ftp client. This was reported to happen on Debian GNU/Linux, kernel
570 version 2.4.3, with `lukemftp' 1.5-5, but might happen on other
571 systems as well. To avoid this problem, switch to using the standard
572 ftp client. On a Debian system, type
574 update-alternatives --config ftp
576 and then choose /usr/bin/netkit-ftp.
578 *** JPEG images aren't displayed.
580 This has been reported when Emacs is built with jpeg-6a library.
581 Upgrading to jpeg-6b solves the problem. Configure checks for the
582 correct version, but this problem could occur if a binary built
583 against a shared libjpeg is run on a system with an older version.
585 *** Dired is very slow.
587 This could happen if invocation of the `df' program takes a long
588 time. Possible reasons for this include:
590 - ClearCase mounted filesystems (VOBs) that sometimes make `df'
591 response time extremely slow (dozens of seconds);
593 - slow automounters on some old versions of Unix;
595 - slow operation of some versions of `df'.
597 To work around the problem, you could either (a) set the variable
598 `directory-free-space-program' to nil, and thus prevent Emacs from
599 invoking `df'; (b) use `df' from the GNU Fileutils package; or
600 (c) use CVS, which is Free Software, instead of ClearCase.
602 *** ps-print commands fail to find prologue files ps-prin*.ps.
604 This can happen if you use an old version of X-Symbol package: it
605 defines compatibility functions which trick ps-print into thinking it
606 runs in XEmacs, and look for the prologue files in a wrong directory.
608 The solution is to upgrade X-Symbol to a later version.
610 *** On systems with shared libraries you might encounter run-time errors
611 from the dynamic linker telling you that it is unable to find some
612 shared libraries, for instance those for Xaw3d or image support.
613 These errors mean Emacs has been linked with a library whose shared
614 library is not in the default search path of the dynamic linker.
616 Similar problems could prevent Emacs from building, since the build
617 process invokes Emacs several times.
619 On many systems, it is possible to set LD_LIBRARY_PATH in your
620 environment to specify additional directories where shared libraries
623 Other systems allow to set LD_RUN_PATH in a similar way, but before
624 Emacs is linked. With LD_RUN_PATH set, the linker will include a
625 specified run-time search path in the executable.
627 On some systems, Emacs can crash due to problems with dynamic
628 linking. Specifically, on SGI Irix 6.5, crashes were reported with
629 backtraces like this:
632 0 strcmp(0xf49239d, 0x4031184, 0x40302b4, 0x12, 0xf0000000, 0xf4923aa, 0x0, 0x492ddb2) ["/xlv22/ficus-jan23/work/irix/lib/libc/libc_n32_M3_ns/strings/strcmp.s":35, 0xfb7e480]
633 1 general_find_symbol(0xf49239d, 0x0, 0x0, 0x0, 0xf0000000, 0xf4923aa, 0x0, 0x492ddb2)
634 ["/comp2/mtibuild/v73/workarea/v7.3/rld/rld.c":2140, 0xfb65a98]
635 2 resolve_symbol(0xf49239d, 0x4031184, 0x0, 0xfbdd438, 0x0, 0xf4923aa, 0x0, 0x492ddb2)
636 ["/comp2/mtibuild/v73/workarea/v7.3/rld/rld.c":1947, 0xfb657e4]
637 3 lazy_text_resolve(0xd18, 0x1a3, 0x40302b4, 0x12, 0xf0000000, 0xf4923aa, 0x0, 0x492ddb2)
638 ["/comp2/mtibuild/v73/workarea/v7.3/rld/rld.c":997, 0xfb64d44]
639 4 _rld_text_resolve(0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0)
640 ["/comp2/mtibuild/v73/workarea/v7.3/rld/rld_bridge.s":175, 0xfb6032c]
642 (`rld' is the dynamic linker.) We don't know yet why this
643 happens, but setting the environment variable LD_BIND_NOW to 1 (which
644 forces the dynamic linker to bind all shared objects early on) seems
645 to work around the problem.
647 Please refer to the documentation of your dynamic linker for details.
649 *** You request inverse video, and the first Emacs frame is in inverse
650 video, but later frames are not in inverse video.
652 This can happen if you have an old version of the custom library in
653 your search path for Lisp packages. Use M-x list-load-path-shadows to
654 check whether this is true. If it is, delete the old custom library.
656 *** When you run Ispell from Emacs, it reports a "misalignment" error.
658 This can happen if you compiled the Ispell program to use ASCII
659 characters only and then try to use it from Emacs with non-ASCII
660 characters, like Latin-1. The solution is to recompile Ispell with
661 support for 8-bit characters.
663 To see whether your Ispell program supports 8-bit characters, type
664 this at your shell's prompt:
668 and look in the output for the string "NO8BIT". If Ispell says
669 "!NO8BIT (8BIT)", your speller supports 8-bit characters; otherwise it
672 To rebuild Ispell with 8-bit character support, edit the local.h file
673 in the Ispell distribution and make sure it does _not_ define NO8BIT.
674 Then rebuild the speller.
676 Another possible cause for "misalignment" error messages is that the
677 version of Ispell installed on your machine is old. Upgrade.
679 Yet another possibility is that you are trying to spell-check a word
680 in a language that doesn't fit the dictionary you choose for use by
681 Ispell. (Ispell can only spell-check one language at a time, because
682 it uses a single dictionary.) Make sure that the text you are
683 spelling and the dictionary used by Ispell conform to each other.
685 If your spell-checking program is Aspell, it has been reported that if
686 you have a personal configuration file (normally ~/.aspell.conf), it
687 can cause this error. Remove that file, execute `ispell-kill-ispell'
688 in Emacs, and then try spell-checking again.
690 * Runtime problems related to font handling
692 ** Characters are displayed as empty boxes or with wrong font under X.
694 *** This can occur when two different versions of FontConfig are used.
695 For example, XFree86 4.3.0 has one version and Gnome usually comes
696 with a newer version. Emacs compiled with Gtk+ will then use the
697 newer version. In most cases the problem can be temporarily fixed by
698 stopping the application that has the error (it can be Emacs or any
699 other application), removing ~/.fonts.cache-1, and then start the
700 application again. If removing ~/.fonts.cache-1 and restarting
701 doesn't help, the application with problem must be recompiled with the
702 same version of FontConfig as the rest of the system uses. For KDE,
703 it is sufficient to recompile Qt.
705 *** Some fonts have a missing glyph and no default character. This is
706 known to occur for character number 160 (no-break space) in some
707 fonts, such as Lucida but Emacs sets the display table for the unibyte
708 and Latin-1 version of this character to display a space.
710 *** Some of the fonts called for in your fontset may not exist on your
713 Each X11 font covers just a fraction of the characters that Emacs
714 supports. To display the whole range of Emacs characters requires
715 many different fonts, collected into a fontset. You can remedy the
716 problem by installing additional fonts.
718 The intlfonts distribution includes a full spectrum of fonts that can
719 display all the characters Emacs supports. The etl-unicode collection
720 of fonts (available from <URL:ftp://ftp.x.org/contrib/fonts/> and
721 <URL:ftp://ftp.xfree86.org/pub/mirror/X.Org/contrib/fonts/>) includes
722 fonts that can display many Unicode characters; they can also be used
723 by ps-print and ps-mule to print Unicode characters.
725 ** Under X11, some characters appear improperly aligned in their lines.
727 You may have bad X11 fonts; try installing the intlfonts distribution
728 or the etl-unicode collection (see above).
730 ** Under X, an unexpected monospace font is used as the default font.
732 When compiled with XFT, Emacs tries to use a default font named
733 "monospace". This is a "virtual font", which the operating system
734 (Fontconfig) redirects to a suitable font such as DejaVu Sans Mono.
735 On some systems, there exists a font that is actually named Monospace,
736 which takes over the virtual font. This is considered an operating
739 http://lists.gnu.org/archive/html/emacs-devel/2008-10/msg00696.html
741 If you encounter this problem, set the default font to a specific font
742 in your .Xresources or initialization file. For instance, you can put
743 the following in your .Xresources:
745 Emacs.font: DejaVu Sans Mono 12
747 ** Certain fonts make each line take one pixel more than it should.
749 This is because these fonts contain characters a little taller than
750 the font's nominal height. Emacs needs to make sure that lines do not
753 ** Loading fonts is very slow.
755 You might be getting scalable fonts instead of precomputed bitmaps.
756 Known scalable font directories are "Type1" and "Speedo". A font
757 directory contains scalable fonts if it contains the file
760 If this is so, re-order your X windows font path to put the scalable
761 font directories last. See the documentation of `xset' for details.
763 With some X servers, it may be necessary to take the scalable font
764 directories out of your path entirely, at least for Emacs 19.26.
765 Changes in the future may make this unnecessary.
767 ** Font Lock displays portions of the buffer in incorrect faces.
769 By far the most frequent cause of this is a parenthesis `(' or a brace
770 `{' in column zero. Font Lock assumes that such a paren is outside of
771 any comment or string. This is of course not true in general, but the
772 vast majority of well-formatted program source files don't have such
773 parens, and therefore this assumption is used to allow optimizations
774 in Font Lock's syntactical analysis. These optimizations avoid some
775 pathological cases where jit-lock, the Just-in-Time fontification
776 introduced with Emacs 21.1, could significantly slow down scrolling
777 through the buffer, especially scrolling backwards, and also jumping
778 to the end of a very large buffer.
780 Beginning with version 22.1, a parenthesis or a brace in column zero
781 is highlighted in bold-red face if it is inside a string or a comment,
782 to indicate that it could interfere with Font Lock (and also with
783 indentation) and should be moved or escaped with a backslash.
785 If you don't use large buffers, or have a very fast machine which
786 makes the delays insignificant, you can avoid the incorrect
787 fontification by setting the variable
788 `font-lock-beginning-of-syntax-function' to a nil value. (This must
789 be done _after_ turning on Font Lock.)
791 Another alternative is to avoid a paren in column zero. For example,
792 in a Lisp string you could precede the paren with a backslash.
794 ** With certain fonts, when the cursor appears on a character, the
795 character doesn't appear--you get a solid box instead.
797 One user on a Linux-based GNU system reported that this problem went
798 away with installation of a new X server. The failing server was
799 XFree86 3.1.1. XFree86 3.1.2 works.
801 ** Emacs pauses for several seconds when changing the default font.
803 This has been reported for fvwm 2.2.5 and the window manager of KDE
804 2.1. The reason for the pause is Xt waiting for a ConfigureNotify
805 event from the window manager, which the window manager doesn't send.
806 Xt stops waiting after a default timeout of usually 5 seconds.
808 A workaround for this is to add something like
810 emacs.waitForWM: false
812 to your X resources. Alternatively, add `(wait-for-wm . nil)' to a
813 frame's parameter list, like this:
815 (modify-frame-parameters nil '((wait-for-wm . nil)))
817 (this should go into your `.emacs' file).
819 ** Underlines appear at the wrong position.
821 This is caused by fonts having a wrong UNDERLINE_POSITION property.
822 Examples are the font 7x13 on XFree prior to version 4.1, or the jmk
823 neep font from the Debian xfonts-jmk package prior to version 3.0.17.
824 To circumvent this problem, set x-use-underline-position-properties
825 to nil in your `.emacs'.
827 To see what is the value of UNDERLINE_POSITION defined by the font,
828 type `xlsfonts -lll FONT' and look at the font's UNDERLINE_POSITION
831 ** When using Exceed, fonts sometimes appear too tall.
833 When the display is set to an Exceed X-server and fonts are specified
834 (either explicitly with the -fn option or implicitly with X resources)
835 then the fonts may appear "too tall". The actual character sizes are
836 correct but there is too much vertical spacing between rows, which
837 gives the appearance of "double spacing".
839 To prevent this, turn off the Exceed's "automatic font substitution"
840 feature (in the font part of the configuration window).
842 ** Subscript/superscript text in TeX is hard to read.
844 If `tex-fontify-script' is non-nil, tex-mode displays
845 subscript/superscript text in the faces subscript/superscript, which
846 are smaller than the normal font and lowered/raised. With some fonts,
847 nested superscripts (say) can be hard to read. Switching to a
848 different font, or changing your antialiasing setting (on an LCD
849 screen), can both make the problem disappear. Alternatively, customize
850 the following variables: tex-font-script-display (how much to
851 lower/raise); tex-suscript-height-ratio (how much smaller than
852 normal); tex-suscript-height-minimum (minimum height).
854 * Internationalization problems
856 ** M-{ does not work on a Spanish PC keyboard.
858 Many Spanish keyboards seem to ignore that combination. Emacs can't
859 do anything about it.
861 ** International characters aren't displayed under X.
865 XFree86 4 contains many fonts in iso10646-1 encoding which have
866 minimal character repertoires (whereas the encoding part of the font
867 name is meant to be a reasonable indication of the repertoire
868 according to the XLFD spec). Emacs may choose one of these to display
869 characters from the mule-unicode charsets and then typically won't be
870 able to find the glyphs to display many characters. (Check with C-u
871 C-x = .) To avoid this, you may need to use a fontset which sets the
872 font for the mule-unicode sets explicitly. E.g. to use GNU unifont,
873 include in the fontset spec:
875 mule-unicode-2500-33ff:-gnu-unifont-*-iso10646-1,\
876 mule-unicode-e000-ffff:-gnu-unifont-*-iso10646-1,\
877 mule-unicode-0100-24ff:-gnu-unifont-*-iso10646-1
879 ** The UTF-8/16/7 coding systems don't encode CJK (Far Eastern) characters.
881 Emacs directly supports the Unicode BMP whose code points are in the
882 ranges 0000-33ff and e000-ffff, and indirectly supports the parts of
883 CJK characters belonging to these legacy charsets:
885 GB2312, Big5, JISX0208, JISX0212, JISX0213-1, JISX0213-2, KSC5601
887 The latter support is done in Utf-Translate-Cjk mode (turned on by
888 default). Which Unicode CJK characters are decoded into which Emacs
889 charset is decided by the current language environment. For instance,
890 in Chinese-GB, most of them are decoded into chinese-gb2312.
892 If you read UTF-8 data with code points outside these ranges, the
893 characters appear in the buffer as raw bytes of the original UTF-8
894 (composed into a single quasi-character) and they will be written back
895 correctly as UTF-8, assuming you don't break the composed sequences.
896 If you read such characters from UTF-16 or UTF-7 data, they are
897 substituted with the Unicode `replacement character', and you lose
900 ** Accented ISO-8859-1 characters are displayed as | or _.
902 Try other font set sizes (S-mouse-1). If the problem persists with
903 other sizes as well, your text is corrupted, probably through software
904 that is not 8-bit clean. If the problem goes away with another font
905 size, it's probably because some fonts pretend to be ISO-8859-1 fonts
906 when they are really ASCII fonts. In particular the schumacher-clean
907 fonts have this bug in some versions of X.
909 To see what glyphs are included in a font, use `xfd', like this:
911 xfd -fn -schumacher-clean-medium-r-normal--12-120-75-75-c-60-iso8859-1
913 If this shows only ASCII glyphs, the font is indeed the source of the
916 The solution is to remove the corresponding lines from the appropriate
917 `fonts.alias' file, then run `mkfontdir' in that directory, and then run
920 ** The `oc-unicode' package doesn't work with Emacs 21.
922 This package tries to define more private charsets than there are free
923 slots now. The current built-in Unicode support is actually more
924 flexible. (Use option `utf-translate-cjk-mode' if you need CJK
925 support.) Files encoded as emacs-mule using oc-unicode aren't
926 generally read correctly by Emacs 21.
928 ** After a while, Emacs slips into unibyte mode.
930 The VM mail package, which is not part of Emacs, sometimes does
931 (standard-display-european t)
932 That should be changed to
933 (standard-display-european 1 t)
937 ** X keyboard problems
939 *** You "lose characters" after typing Compose Character key.
941 This is because the Compose Character key is defined as the keysym
942 Multi_key, and Emacs (seeing that) does the proper X11
943 character-composition processing. If you don't want your Compose key
944 to do that, you can redefine it with xmodmap.
946 For example, here's one way to turn it into a Meta key:
948 xmodmap -e "keysym Multi_key = Meta_L"
950 If all users at your site of a particular keyboard prefer Meta to
951 Compose, you can make the remapping happen automatically by adding the
952 xmodmap command to the xdm setup script for that display.
954 *** Using X Windows, control-shift-leftbutton makes Emacs hang.
956 Use the shell command `xset bc' to make the old X Menu package work.
958 *** C-SPC fails to work on Fedora GNU/Linux (or with fcitx input method).
960 Fedora Core 4 steals the C-SPC key by default for the `iiimx' program
961 which is the input method for some languages. It blocks Emacs users
962 from using the C-SPC key for `set-mark-command'.
964 One solutions is to remove the `<Ctrl>space' from the `Iiimx' file
965 which can be found in the `/usr/lib/X11/app-defaults' directory.
966 However, that requires root access.
968 Another is to specify `Emacs*useXIM: false' in your X resources.
970 Another is to build Emacs with the `--without-xim' configure option.
972 The same problem happens on any other system if you are using fcitx
973 (Chinese input method) which by default use C-SPC for toggling. If
974 you want to use fcitx with Emacs, you have two choices. Toggle fcitx
975 by another key (e.g. C-\) by modifying ~/.fcitx/config, or be
976 accustomed to use C-@ for `set-mark-command'.
978 *** M-SPC seems to be ignored as input.
980 See if your X server is set up to use this as a command
981 for character composition.
983 *** The S-C-t key combination doesn't get passed to Emacs on X.
985 This happens because some X configurations assign the Ctrl-Shift-t
986 combination the same meaning as the Multi_key. The offending
987 definition is in the file `...lib/X11/locale/iso8859-1/Compose'; there
988 might be other similar combinations which are grabbed by X for similar
991 We think that this can be countermanded with the `xmodmap' utility, if
992 you want to be able to bind one of these key sequences within Emacs.
994 *** Under X, C-v and/or other keys don't work.
996 These may have been intercepted by your window manager. In
997 particular, AfterStep 1.6 is reported to steal C-v in its default
998 configuration. Various Meta keys are also likely to be taken by the
999 configuration of the `feel'. See the WM's documentation for how to
1002 *** Clicking C-mouse-2 in the scroll bar doesn't split the window.
1004 This currently doesn't work with scroll-bar widgets (and we don't know
1005 a good way of implementing it with widgets). If Emacs is configured
1006 --without-toolkit-scroll-bars, C-mouse-2 on the scroll bar does work.
1008 *** Inability to send an Alt-modified key, when Emacs is communicating
1009 directly with an X server.
1011 If you have tried to bind an Alt-modified key as a command, and it
1012 does not work to type the command, the first thing you should check is
1013 whether the key is getting through to Emacs. To do this, type C-h c
1014 followed by the Alt-modified key. C-h c should say what kind of event
1015 it read. If it says it read an Alt-modified key, then make sure you
1016 have made the key binding correctly.
1018 If C-h c reports an event that doesn't have the Alt modifier, it may
1019 be because your X server has no key for the Alt modifier. The X
1020 server that comes from MIT does not set up the Alt modifier by
1023 If your keyboard has keys named Alt, you can enable them as follows:
1025 xmodmap -e 'add mod2 = Alt_L'
1026 xmodmap -e 'add mod2 = Alt_R'
1028 If the keyboard has just one key named Alt, then only one of those
1029 commands is needed. The modifier `mod2' is a reasonable choice if you
1030 are using an unmodified MIT version of X. Otherwise, choose any
1031 modifier bit not otherwise used.
1033 If your keyboard does not have keys named Alt, you can use some other
1034 keys. Use the keysym command in xmodmap to turn a function key (or
1035 some other 'spare' key) into Alt_L or into Alt_R, and then use the
1036 commands show above to make them modifier keys.
1038 Note that if you have Alt keys but no Meta keys, Emacs translates Alt
1039 into Meta. This is because of the great importance of Meta in Emacs.
1041 ** Window-manager and toolkit-related problems
1043 *** Metacity: Resizing Emacs or ALT-Tab causes X to be unresponsive.
1045 This happens sometimes when using Metacity. Resizing Emacs or ALT-Tab:bing
1046 makes the system unresponsive to the mouse or the keyboard. Killing Emacs
1047 or shifting out from X11 and back again usually cures it (i.e. Ctrl-Alt-F1
1048 and then Alt-F7). A bug for it is here:
1049 https://bugs.launchpad.net/ubuntu/+source/metacity/+bug/231034.
1050 Note that a permanent fix seems to be to disable "assistive technologies".
1052 *** Gnome: Emacs receives input directly from the keyboard, bypassing XIM.
1054 This seems to happen when gnome-settings-daemon version 2.12 or later
1055 is running. If gnome-settings-daemon is not running, Emacs receives
1056 input through XIM without any problem. Furthermore, this seems only
1057 to happen in *.UTF-8 locales; zh_CN.GB2312 and zh_CN.GBK locales, for
1058 example, work fine. A bug report has been filed in the Gnome
1059 bugzilla: http://bugzilla.gnome.org/show_bug.cgi?id=357032
1061 *** Gnome: Emacs' xterm-mouse-mode doesn't work on the Gnome terminal.
1063 A symptom of this bug is that double-clicks insert a control sequence
1064 into the buffer. The reason this happens is an apparent
1065 incompatibility of the Gnome terminal with Xterm, which also affects
1066 other programs using the Xterm mouse interface. A problem report has
1069 *** KDE: When running on KDE, colors or fonts are not as specified for Emacs,
1072 For example, you could see background you set for Emacs only in the
1073 empty portions of the Emacs display, while characters have some other
1076 This happens because KDE's defaults apply its color and font
1077 definitions even to applications that weren't compiled for KDE. The
1078 solution is to uncheck the "Apply fonts and colors to non-KDE apps"
1079 option in Preferences->Look&Feel->Style (KDE 2). In KDE 3, this option
1080 is in the "Colors" section, rather than "Style".
1082 Alternatively, if you do want the KDE defaults to apply to other
1083 applications, but not to Emacs, you could modify the file `Emacs.ad'
1084 (should be in the `/usr/share/apps/kdisplay/app-defaults/' directory)
1085 so that it doesn't set the default background and foreground only for
1086 Emacs. For example, make sure the following resources are either not
1087 present or commented out:
1089 Emacs.default.attributeForeground
1090 Emacs.default.attributeBackground
1094 It is also reported that a bug in the gtk-engines-qt engine can cause this if
1095 Emacs is compiled with Gtk+.
1096 The bug is fixed in version 0.7 or newer of gtk-engines-qt.
1098 *** KDE: Emacs hangs on KDE when a large portion of text is killed.
1100 This is caused by a bug in the KDE applet `klipper' which periodically
1101 requests the X clipboard contents from applications. Early versions
1102 of klipper don't implement the ICCCM protocol for large selections,
1103 which leads to Emacs being flooded with selection requests. After a
1104 while, Emacs may print a message:
1106 Timed out waiting for property-notify event
1108 A workaround is to not use `klipper'. An upgrade to the `klipper' that
1109 comes with KDE 3.3 or later also solves the problem.
1111 *** CDE: Frames may cover dialogs they created when using CDE.
1113 This can happen if you have "Allow Primary Windows On Top" enabled which
1114 seems to be the default in the Common Desktop Environment.
1115 To change, go in to "Desktop Controls" -> "Window Style Manager"
1116 and uncheck "Allow Primary Windows On Top".
1118 *** Xaw3d : When using Xaw3d scroll bars without arrows, the very first mouse
1119 click in a scroll bar might be ignored by the scroll bar widget. This
1120 is probably a bug in Xaw3d; when Xaw3d is compiled with arrows, the
1123 *** Xaw: There are known binary incompatibilities between Xaw, Xaw3d, neXtaw,
1124 XawM and the few other derivatives of Xaw. So when you compile with
1125 one of these, it may not work to dynamically link with another one.
1126 For example, strange problems, such as Emacs exiting when you type
1127 "C-x 1", were reported when Emacs compiled with Xaw3d and libXaw was
1128 used with neXtaw at run time.
1130 The solution is to rebuild Emacs with the toolkit version you actually
1131 want to use, or set LD_PRELOAD to preload the same toolkit version you
1134 *** Open Motif: Problems with file dialogs in Emacs built with Open Motif.
1136 When Emacs 21 is built with Open Motif 2.1, it can happen that the
1137 graphical file dialog boxes do not work properly. The "OK", "Filter"
1138 and "Cancel" buttons do not respond to mouse clicks. Dragging the
1139 file dialog window usually causes the buttons to work again.
1141 The solution is to use LessTif instead. LessTif is a free replacement
1142 for Motif. See the file INSTALL for information on how to do this.
1144 Another workaround is not to use the mouse to trigger file prompts,
1145 but to use the keyboard. This way, you will be prompted for a file in
1146 the minibuffer instead of a graphical file dialog.
1148 *** LessTif: Problems in Emacs built with LessTif.
1150 The problems seem to depend on the version of LessTif and the Motif
1151 emulation for which it is set up.
1153 Only the Motif 1.2 emulation seems to be stable enough in LessTif.
1154 LessTif 0.92-17's Motif 1.2 emulation seems to work okay on FreeBSD.
1155 On GNU/Linux systems, lesstif-0.92.6 configured with "./configure
1156 --enable-build-12 --enable-default-12" is reported to be the most
1157 successful. The binary GNU/Linux package
1158 lesstif-devel-0.92.0-1.i386.rpm was reported to have problems with
1161 On some systems, even with Motif 1.2 emulation, Emacs occasionally
1162 locks up, grabbing all mouse and keyboard events. We still don't know
1163 what causes these problems; they are not reproducible by Emacs
1166 *** Motif: The Motif version of Emacs paints the screen a solid color.
1168 This has been observed to result from the following X resource:
1170 Emacs*default.attributeFont: -*-courier-medium-r-*-*-*-140-*-*-*-*-iso8859-*
1172 That the resource has this effect indicates a bug in something, but we
1173 do not yet know what. If it is an Emacs bug, we hope someone can
1174 explain what the bug is so we can fix it. In the mean time, removing
1175 the resource prevents the problem.
1177 ** General X problems
1179 *** Redisplay using X11 is much slower than previous Emacs versions.
1181 We've noticed that certain X servers draw the text much slower when
1182 scroll bars are on the left. We don't know why this happens. If this
1183 happens to you, you can work around it by putting the scroll bars
1184 on the right (as they were in Emacs 19).
1186 Here's how to do this:
1188 (set-scroll-bar-mode 'right)
1190 If you're not sure whether (or how much) this problem affects you,
1191 try that and see how much difference it makes. To set things back
1194 (set-scroll-bar-mode 'left)
1196 *** Error messages about undefined colors on X.
1198 The messages might say something like this:
1200 Unable to load color "grey95"
1202 (typically, in the `*Messages*' buffer), or something like this:
1204 Error while displaying tooltip: (error Undefined color lightyellow)
1206 These problems could happen if some other X program has used up too
1207 many colors of the X palette, leaving Emacs with insufficient system
1208 resources to load all the colors it needs.
1210 A solution is to exit the offending X programs before starting Emacs.
1212 "undefined color" messages can also occur if the RgbPath entry in the
1213 X configuration file is incorrect, or the rgb.txt file is not where
1214 X expects to find it.
1216 *** Improving performance with slow X connections.
1218 There are several ways to improve this performance, any subset of which can
1219 be carried out at the same time:
1221 1) If you don't need X Input Methods (XIM) for entering text in some
1222 language you use, you can improve performance on WAN links by using
1223 the X resource useXIM to turn off use of XIM. This does not affect
1224 the use of Emacs' own input methods, which are part of the Leim
1227 2) If the connection is very slow, you might also want to consider
1228 switching off scroll bars, menu bar, and tool bar. Adding the
1229 following forms to your .emacs file will accomplish that, but only
1230 after the the initial frame is displayed:
1232 (scroll-bar-mode -1)
1236 For still quicker startup, put these X resources in your .Xdefaults
1239 Emacs.verticalScrollBars: off
1243 3) Use ssh to forward the X connection, and enable compression on this
1244 forwarded X connection (ssh -XC remotehostname emacs ...).
1246 4) Use lbxproxy on the remote end of the connection. This is an interface
1247 to the low bandwidth X extension in most modern X servers, which
1248 improves performance dramatically, at the slight expense of correctness
1249 of the X protocol. lbxproxy acheives the performance gain by grouping
1250 several X requests in one TCP packet and sending them off together,
1251 instead of requiring a round-trip for each X request in a separate
1252 packet. The switches that seem to work best for emacs are:
1253 -noatomsfile -nowinattr -cheaterrors -cheatevents
1254 Note that the -nograbcmap option is known to cause problems.
1255 For more about lbxproxy, see:
1256 http://www.xfree86.org/4.3.0/lbxproxy.1.html
1258 5) If copying and killing is slow, try to disable the interaction with the
1259 native system's clipboard by adding these lines to your .emacs file:
1260 (setq interprogram-cut-function nil)
1261 (setq interprogram-paste-function nil)
1263 *** Emacs gives the error, Couldn't find per display information.
1265 This can result if the X server runs out of memory because Emacs uses
1266 a large number of fonts. On systems where this happens, C-h h is
1269 We do not know of a way to prevent the problem.
1271 *** Emacs does not notice when you release the mouse.
1273 There are reports that this happened with (some) Microsoft mice and
1274 that replacing the mouse made it stop.
1276 *** You can't select from submenus (in the X toolkit version).
1278 On certain systems, mouse-tracking and selection in top-level menus
1279 works properly with the X toolkit, but neither of them works when you
1280 bring up a submenu (such as Bookmarks or Compare or Apply Patch, in
1283 This works on most systems. There is speculation that the failure is
1284 due to bugs in old versions of X toolkit libraries, but no one really
1285 knows. If someone debugs this and finds the precise cause, perhaps a
1286 workaround can be found.
1288 *** An error message such as `X protocol error: BadMatch (invalid
1289 parameter attributes) on protocol request 93'.
1291 This comes from having an invalid X resource, such as
1293 (which is invalid because it specifies a color name for something
1294 that isn't a color.)
1296 The fix is to correct your X resources.
1298 *** Slow startup on X11R6 with X windows.
1300 If Emacs takes two minutes to start up on X11R6, see if your X
1301 resources specify any Adobe fonts. That causes the type-1 font
1302 renderer to start up, even if the font you asked for is not a type-1
1305 One way to avoid this problem is to eliminate the type-1 fonts from
1306 your font path, like this:
1308 xset -fp /usr/X11R6/lib/X11/fonts/Type1/
1310 *** Pull-down menus appear in the wrong place, in the toolkit version of Emacs.
1312 An X resource of this form can cause the problem:
1314 Emacs*geometry: 80x55+0+0
1316 This resource is supposed to apply, and does apply, to the menus
1317 individually as well as to Emacs frames. If that is not what you
1318 want, rewrite the resource.
1320 To check thoroughly for such resource specifications, use `xrdb
1321 -query' to see what resources the X server records, and also look at
1322 the user's ~/.Xdefaults and ~/.Xdefaults-* files.
1324 *** Emacs running under X Windows does not handle mouse clicks.
1325 *** `emacs -geometry 80x20' finds a file named `80x20'.
1327 One cause of such problems is having (setq term-file-prefix nil) in
1328 your .emacs file. Another cause is a bad value of EMACSLOADPATH in
1331 *** X Windows doesn't work if DISPLAY uses a hostname.
1333 People have reported kernel bugs in certain systems that cause Emacs
1334 not to work with X Windows if DISPLAY is set using a host name. But
1335 the problem does not occur if DISPLAY is set to `unix:0.0'. I think
1336 the bug has to do with SIGIO or FIONREAD.
1338 You may be able to compensate for the bug by doing (set-input-mode nil nil).
1339 However, that has the disadvantage of turning off interrupts, so that
1340 you are unable to quit out of a Lisp program by typing C-g.
1342 *** Prevent double pastes in X
1344 The problem: a region, such as a command, is pasted twice when you copy
1345 it with your mouse from GNU Emacs to an xterm or an RXVT shell in X.
1346 The solution: try the following in your X configuration file,
1347 /etc/X11/xorg.conf This should enable both PS/2 and USB mice for
1348 single copies. You do not need any other drivers or options.
1350 Section "InputDevice"
1351 Identifier "Generic Mouse"
1353 Option "Device" "/dev/input/mice"
1356 * Runtime problems on character terminals
1358 ** The meta key does not work on xterm.
1359 Typing M-x rings the terminal bell, and inserts a string like ";120~".
1360 For recent xterm versions (>= 216), Emacs uses xterm's modifyOtherKeys
1361 feature to generate strings for key combinations that are not
1362 otherwise usable. One circumstance in which this can cause problems
1363 is if you have specified the X resource
1365 xterm*VT100.Translations
1367 to contain translations that use the meta key. Then xterm will not
1368 use meta in modified function-keys, which confuses Emacs. To fix
1369 this, you can remove the X resource or put this in your init file:
1371 (xterm-remove-modify-other-keys)
1373 ** Emacs spontaneously displays "I-search: " at the bottom of the screen.
1375 This means that Control-S/Control-Q (XON/XOFF) "flow control" is being
1376 used. C-s/C-q flow control is bad for Emacs editors because it takes
1377 away C-s and C-q as user commands. Since editors do not output long
1378 streams of text without user commands, there is no need for a
1379 user-issuable "stop output" command in an editor; therefore, a
1380 properly designed flow control mechanism would transmit all possible
1381 input characters without interference. Designing such a mechanism is
1382 easy, for a person with at least half a brain.
1384 There are three possible reasons why flow control could be taking place:
1386 1) Terminal has not been told to disable flow control
1387 2) Insufficient padding for the terminal in use
1388 3) Some sort of terminal concentrator or line switch is responsible
1390 First of all, many terminals have a set-up mode which controls whether
1391 they generate XON/XOFF flow control characters. This must be set to
1392 "no XON/XOFF" in order for Emacs to work. (For example, on a VT220
1393 you may select "No XOFF" in the setup menu.) Sometimes there is an
1394 escape sequence that the computer can send to turn flow control off
1395 and on. If so, perhaps the termcap `ti' string should turn flow
1396 control off, and the `te' string should turn it on.
1398 Once the terminal has been told "no flow control", you may find it
1399 needs more padding. The amount of padding Emacs sends is controlled
1400 by the termcap entry for the terminal in use, and by the output baud
1401 rate as known by the kernel. The shell command `stty' will print
1402 your output baud rate; `stty' with suitable arguments will set it if
1403 it is wrong. Setting to a higher speed causes increased padding. If
1404 the results are wrong for the correct speed, there is probably a
1405 problem in the termcap entry. You must speak to a local Unix wizard
1406 to fix this. Perhaps you are just using the wrong terminal type.
1408 For terminals that lack a "no flow control" mode, sometimes just
1409 giving lots of padding will prevent actual generation of flow control
1410 codes. You might as well try it.
1412 If you are really unlucky, your terminal is connected to the computer
1413 through a concentrator which sends XON/XOFF flow control to the
1414 computer, or it insists on sending flow control itself no matter how
1415 much padding you give it. Unless you can figure out how to turn flow
1416 control off on this concentrator (again, refer to your local wizard),
1417 you are screwed! You should have the terminal or concentrator
1418 replaced with a properly designed one. In the mean time, some drastic
1419 measures can make Emacs semi-work.
1421 You can make Emacs ignore C-s and C-q and let the operating system
1422 handle them. To do this on a per-session basis, just type M-x
1423 enable-flow-control RET. You will see a message that C-\ and C-^ are
1424 now translated to C-s and C-q. (Use the same command M-x
1425 enable-flow-control to turn *off* this special mode. It toggles flow
1428 If C-\ and C-^ are inconvenient for you (for example, if one of them
1429 is the escape character of your terminal concentrator), you can choose
1430 other characters by setting the variables flow-control-c-s-replacement
1431 and flow-control-c-q-replacement. But choose carefully, since all
1432 other control characters are already used by emacs.
1434 IMPORTANT: if you type C-s by accident while flow control is enabled,
1435 Emacs output will freeze, and you will have to remember to type C-q in
1438 If you work in an environment where a majority of terminals of a
1439 certain type are flow control hobbled, you can use the function
1440 `enable-flow-control-on' to turn on this flow control avoidance scheme
1441 automatically. Here is an example:
1443 (enable-flow-control-on "vt200" "vt300" "vt101" "vt131")
1445 If this isn't quite correct (e.g. you have a mixture of flow-control hobbled
1446 and good vt200 terminals), you can still run enable-flow-control
1449 I have no intention of ever redesigning the Emacs command set for the
1450 assumption that terminals use C-s/C-q flow control. XON/XOFF flow
1451 control technique is a bad design, and terminals that need it are bad
1452 merchandise and should not be purchased. Now that X is becoming
1453 widespread, XON/XOFF seems to be on the way out. If you can get some
1454 use out of GNU Emacs on inferior terminals, more power to you, but I
1455 will not make Emacs worse for properly designed systems for the sake
1456 of inferior systems.
1458 ** Control-S and Control-Q commands are ignored completely.
1460 For some reason, your system is using brain-damaged C-s/C-q flow
1461 control despite Emacs's attempts to turn it off. Perhaps your
1462 terminal is connected to the computer through a concentrator
1463 that wants to use flow control.
1465 You should first try to tell the concentrator not to use flow control.
1466 If you succeed in this, try making the terminal work without
1467 flow control, as described in the preceding section.
1469 If that line of approach is not successful, map some other characters
1470 into C-s and C-q using keyboard-translate-table. The example above
1471 shows how to do this with C-^ and C-\.
1473 ** Screen is updated wrong, but only on one kind of terminal.
1475 This could mean that the termcap entry you are using for that
1476 terminal is wrong, or it could mean that Emacs has a bug handing
1477 the combination of features specified for that terminal.
1479 The first step in tracking this down is to record what characters
1480 Emacs is sending to the terminal. Execute the Lisp expression
1481 (open-termscript "./emacs-script") to make Emacs write all
1482 terminal output into the file ~/emacs-script as well; then do
1483 what makes the screen update wrong, and look at the file
1484 and decode the characters using the manual for the terminal.
1485 There are several possibilities:
1487 1) The characters sent are correct, according to the terminal manual.
1489 In this case, there is no obvious bug in Emacs, and most likely you
1490 need more padding, or possibly the terminal manual is wrong.
1492 2) The characters sent are incorrect, due to an obscure aspect
1493 of the terminal behavior not described in an obvious way
1496 This case is hard. It will be necessary to think of a way for
1497 Emacs to distinguish between terminals with this kind of behavior
1498 and other terminals that behave subtly differently but are
1499 classified the same by termcap; or else find an algorithm for
1500 Emacs to use that avoids the difference. Such changes must be
1501 tested on many kinds of terminals.
1503 3) The termcap entry is wrong.
1505 See the file etc/TERMS for information on changes
1506 that are known to be needed in commonly used termcap entries
1507 for certain terminals.
1509 4) The characters sent are incorrect, and clearly cannot be
1510 right for any terminal with the termcap entry you were using.
1512 This is unambiguously an Emacs bug, and can probably be fixed
1513 in termcap.c, tparam.c, term.c, scroll.c, cm.c or dispnew.c.
1515 ** Control-S and Control-Q commands are ignored completely on a net connection.
1517 Some versions of rlogin (and possibly telnet) do not pass flow
1518 control characters to the remote system to which they connect.
1519 On such systems, emacs on the remote system cannot disable flow
1520 control on the local system. Sometimes `rlogin -8' will avoid this
1523 One way to cure this is to disable flow control on the local host
1524 (the one running rlogin, not the one running rlogind) using the
1525 stty command, before starting the rlogin process. On many systems,
1526 "stty start u stop u" will do this. On some systems, use
1527 "stty -ixon" instead.
1529 Some versions of tcsh will prevent even this from working. One way
1530 around this is to start another shell before starting rlogin, and
1531 issue the stty command to disable flow control from that shell.
1533 If none of these methods work, the best solution is to type
1534 M-x enable-flow-control at the beginning of your emacs session, or
1535 if you expect the problem to continue, add a line such as the
1536 following to your .emacs (on the host running rlogind):
1538 (enable-flow-control-on "vt200" "vt300" "vt101" "vt131")
1540 See the entry about spontaneous display of I-search (above) for more
1543 ** Output from Control-V is slow.
1545 On many bit-map terminals, scrolling operations are fairly slow.
1546 Often the termcap entry for the type of terminal in use fails
1547 to inform Emacs of this. The two lines at the bottom of the screen
1548 before a Control-V command are supposed to appear at the top after
1549 the Control-V command. If Emacs thinks scrolling the lines is fast,
1550 it will scroll them to the top of the screen.
1552 If scrolling is slow but Emacs thinks it is fast, the usual reason is
1553 that the termcap entry for the terminal you are using does not
1554 specify any padding time for the `al' and `dl' strings. Emacs
1555 concludes that these operations take only as much time as it takes to
1556 send the commands at whatever line speed you are using. You must
1557 fix the termcap entry to specify, for the `al' and `dl', as much
1558 time as the operations really take.
1560 Currently Emacs thinks in terms of serial lines which send characters
1561 at a fixed rate, so that any operation which takes time for the
1562 terminal to execute must also be padded. With bit-map terminals
1563 operated across networks, often the network provides some sort of
1564 flow control so that padding is never needed no matter how slow
1565 an operation is. You must still specify a padding time if you want
1566 Emacs to realize that the operation takes a long time. This will
1567 cause padding characters to be sent unnecessarily, but they do
1568 not really cost much. They will be transmitted while the scrolling
1569 is happening and then discarded quickly by the terminal.
1571 Most bit-map terminals provide commands for inserting or deleting
1572 multiple lines at once. Define the `AL' and `DL' strings in the
1573 termcap entry to say how to do these things, and you will have
1574 fast output without wasted padding characters. These strings should
1575 each contain a single %-spec saying how to send the number of lines
1576 to be scrolled. These %-specs are like those in the termcap
1579 You should also define the `IC' and `DC' strings if your terminal
1580 has a command to insert or delete multiple characters. These
1581 take the number of positions to insert or delete as an argument.
1583 A `cs' string to set the scrolling region will reduce the amount
1584 of motion you see on the screen when part of the screen is scrolled.
1586 ** You type Control-H (Backspace) expecting to delete characters.
1588 Put `stty dec' in your .login file and your problems will disappear
1591 The choice of Backspace for erasure was based on confusion, caused by
1592 the fact that backspacing causes erasure (later, when you type another
1593 character) on most display terminals. But it is a mistake. Deletion
1594 of text is not the same thing as backspacing followed by failure to
1595 overprint. I do not wish to propagate this confusion by conforming
1598 For this reason, I believe `stty dec' is the right mode to use,
1599 and I have designed Emacs to go with that. If there were a thousand
1600 other control characters, I would define Control-h to delete as well;
1601 but there are not very many other control characters, and I think
1602 that providing the most mnemonic possible Help character is more
1603 important than adapting to people who don't use `stty dec'.
1605 If you are obstinate about confusing buggy overprinting with deletion,
1606 you can redefine Backspace in your .emacs file:
1607 (global-set-key "\b" 'delete-backward-char)
1608 You can probably access help-command via f1.
1610 ** Colors are not available on a tty or in xterm.
1612 Emacs 21 supports colors on character terminals and terminal
1613 emulators, but this support relies on the terminfo or termcap database
1614 entry to specify that the display supports color. Emacs looks at the
1615 "Co" capability for the terminal to find out how many colors are
1616 supported; it should be non-zero to activate the color support within
1617 Emacs. (Most color terminals support 8 or 16 colors.) If your system
1618 uses terminfo, the name of the capability equivalent to "Co" is
1621 In addition to the "Co" capability, Emacs needs the "op" (for
1622 ``original pair'') capability, which tells how to switch the terminal
1623 back to the default foreground and background colors. Emacs will not
1624 use colors if this capability is not defined. If your terminal entry
1625 doesn't provide such a capability, try using the ANSI standard escape
1626 sequence \E[00m (that is, define a new termcap/terminfo entry and make
1627 it use your current terminal's entry plus \E[00m for the "op"
1630 Finally, the "NC" capability (terminfo name: "ncv") tells Emacs which
1631 attributes cannot be used with colors. Setting this capability
1632 incorrectly might have the effect of disabling colors; try setting
1633 this capability to `0' (zero) and see if that helps.
1635 Emacs uses the database entry for the terminal whose name is the value
1636 of the environment variable TERM. With `xterm', a common terminal
1637 entry that supports color is `xterm-color', so setting TERM's value to
1638 `xterm-color' might activate the color support on an xterm-compatible
1641 Beginning with version 22.1, Emacs supports the --color command-line
1642 option which may be used to force Emacs to use one of a few popular
1643 modes for getting colors on a tty. For example, --color=ansi8 sets up
1644 for using the ANSI-standard escape sequences that support 8 colors.
1646 Some modes do not use colors unless you turn on the Font-lock mode.
1647 Some people have long ago set their `~/.emacs' files to turn on
1648 Font-lock on X only, so they won't see colors on a tty. The
1649 recommended way of turning on Font-lock is by typing "M-x
1650 global-font-lock-mode RET" or by customizing the variable
1651 `global-font-lock-mode'.
1653 * Runtime problems specific to individual Unix variants
1657 *** GNU/Linux: Process output is corrupted.
1659 There is a bug in Linux kernel 2.6.10 PTYs that can cause emacs to
1660 read corrupted process output.
1662 *** GNU/Linux: Remote access to CVS with SSH causes file corruption.
1664 If you access a remote CVS repository via SSH, files may be corrupted
1665 due to bad interaction between CVS, SSH, and libc.
1667 To fix the problem, save the following script into a file, make it
1668 executable, and set CVS_RSH environment variable to the file name of
1672 exec 2> >(exec cat >&2 2>/dev/null)
1675 *** GNU/Linux: On Linux-based GNU systems using libc versions 5.4.19 through
1676 5.4.22, Emacs crashes at startup with a segmentation fault.
1678 This problem happens if libc defines the symbol __malloc_initialized.
1679 One known solution is to upgrade to a newer libc version. 5.4.33 is
1682 *** GNU/Linux: After upgrading to a newer version of Emacs,
1683 the Meta key stops working.
1685 This was reported to happen on a GNU/Linux system distributed by
1686 Mandrake. The reason is that the previous version of Emacs was
1687 modified by Mandrake to make the Alt key act as the Meta key, on a
1688 keyboard where the Windows key is the one which produces the Meta
1689 modifier. A user who started using a newer version of Emacs, which
1690 was not hacked by Mandrake, expected the Alt key to continue to act as
1691 Meta, and was astonished when that didn't happen.
1693 The solution is to find out what key on your keyboard produces the Meta
1694 modifier, and use that key instead. Try all of the keys to the left
1695 and to the right of the space bar, together with the `x' key, and see
1696 which combination produces "M-x" in the echo area. You can also use
1697 the `xmodmap' utility to show all the keys which produce a Meta
1700 xmodmap -pk | egrep -i "meta|alt"
1702 A more convenient way of finding out which keys produce a Meta modifier
1703 is to use the `xkbprint' utility, if it's available on your system:
1705 xkbprint 0:0 /tmp/k.ps
1707 This produces a PostScript file `/tmp/k.ps' with a picture of your
1708 keyboard; printing that file on a PostScript printer will show what
1709 keys can serve as Meta.
1711 The `xkeycaps' also shows a visual representation of the current
1712 keyboard settings. It also allows to modify them.
1714 *** GNU/Linux: slow startup on Linux-based GNU systems.
1716 People using systems based on the Linux kernel sometimes report that
1717 startup takes 10 to 15 seconds longer than `usual'.
1719 This is because Emacs looks up the host name when it starts.
1720 Normally, this takes negligible time; the extra delay is due to
1721 improper system configuration. This problem can occur for both
1722 networked and non-networked machines.
1724 Here is how to fix the configuration. It requires being root.
1726 **** Networked Case.
1728 First, make sure the files `/etc/hosts' and `/etc/host.conf' both
1729 exist. The first line in the `/etc/hosts' file should look like this
1730 (replace HOSTNAME with your host name):
1734 Also make sure that the `/etc/host.conf' files contains the following
1740 Any changes, permanent and temporary, to the host name should be
1741 indicated in the `/etc/hosts' file, since it acts a limited local
1742 database of addresses and names (e.g., some SLIP connections
1743 dynamically allocate ip addresses).
1745 **** Non-Networked Case.
1747 The solution described in the networked case applies here as well.
1748 However, if you never intend to network your machine, you can use a
1749 simpler solution: create an empty `/etc/host.conf' file. The command
1750 `touch /etc/host.conf' suffices to create the file. The `/etc/hosts'
1751 file is not necessary with this approach.
1753 *** GNU/Linux: Emacs on a tty switches the cursor to large blinking block.
1755 This was reported to happen on some GNU/Linux systems which use
1756 ncurses version 5.0, but could be relevant for other versions as well.
1757 These versions of ncurses come with a `linux' terminfo entry, where
1758 the "cvvis" capability (termcap "vs") is defined as "\E[?25h\E[?8c"
1759 (show cursor, change size). This escape sequence switches on a
1760 blinking hardware text-mode cursor whose size is a full character
1761 cell. This blinking cannot be stopped, since a hardware cursor
1764 A work-around is to redefine the "cvvis" capability so that it
1765 enables a *software* cursor. The software cursor works by inverting
1766 the colors of the character at point, so what you see is a block
1767 cursor that doesn't blink. For this to work, you need to redefine
1768 the "cnorm" capability as well, so that it operates on the software
1769 cursor instead of the hardware cursor.
1771 To this end, run "infocmp linux > linux-term", edit the file
1772 `linux-term' to make both the "cnorm" and "cvvis" capabilities send
1773 the sequence "\E[?25h\E[?17;0;64c", and then run "tic linux-term" to
1774 produce a modified terminfo entry.
1776 Alternatively, if you want a blinking underscore as your Emacs cursor,
1777 change the "cvvis" capability to send the "\E[?25h\E[?0c" command.
1779 *** GNU/Linux: Error messages `internal facep []' happen on GNU/Linux systems.
1781 There is a report that replacing libc.so.5.0.9 with libc.so.5.2.16
1782 caused this to start happening. People are not sure why, but the
1783 problem seems unlikely to be in Emacs itself. Some suspect that it
1784 is actually Xlib which won't work with libc.so.5.2.16.
1786 Using the old library version is a workaround.
1790 *** FreeBSD 2.1.5: useless symbolic links remain in /tmp or other
1791 directories that have the +t bit.
1793 This is because of a kernel bug in FreeBSD 2.1.5 (fixed in 2.2).
1794 Emacs uses symbolic links to implement file locks. In a directory
1795 with +t bit, the directory owner becomes the owner of the symbolic
1796 link, so that it cannot be removed by anyone else.
1798 If you don't like those useless links, you can let Emacs not to using
1799 file lock by adding #undef CLASH_DETECTION to config.h.
1801 *** FreeBSD: Getting a Meta key on the console.
1803 By default, neither Alt nor any other key acts as a Meta key on
1804 FreeBSD, but this can be changed using kbdcontrol(1). Dump the
1805 current keymap to a file with the command
1807 $ kbdcontrol -d >emacs.kbd
1809 Edit emacs.kbd, and give the key you want to be the Meta key the
1810 definition `meta'. For instance, if your keyboard has a ``Windows''
1811 key with scan code 105, change the line for scan code 105 in emacs.kbd
1814 105 meta meta meta meta meta meta meta meta O
1816 to make the Windows key the Meta key. Load the new keymap with
1818 $ kbdcontrol -l emacs.kbd
1822 *** HP/UX : Shell mode gives the message, "`tty`: Ambiguous".
1824 christos@theory.tn.cornell.edu says:
1826 The problem is that in your .cshrc you have something that tries to
1827 execute `tty`. If you are not running the shell on a real tty then
1828 tty will print "not a tty". Csh expects one word in some places,
1829 but tty is giving it back 3.
1831 The solution is to add a pair of quotes around `tty` to make it a single
1834 if (`tty` == "/dev/console")
1836 should be changed to:
1838 if ("`tty`" == "/dev/console")
1840 Even better, move things that set up terminal sections out of .cshrc
1843 *** HP/UX: `Pid xxx killed due to text modification or page I/O error'.
1845 On HP/UX, you can get that error when the Emacs executable is on an NFS
1846 file system. HP/UX responds this way if it tries to swap in a page and
1847 does not get a response from the server within a timeout whose default
1848 value is just ten seconds.
1850 If this happens to you, extend the timeout period.
1852 *** HP/UX: The right Alt key works wrong on German HP keyboards (and perhaps
1853 other non-English HP keyboards too).
1855 This is because HP-UX defines the modifiers wrong in X. Here is a
1856 shell script to fix the problem; be sure that it is run after VUE
1857 configures the X server.
1859 xmodmap 2> /dev/null - << EOF
1860 keysym Alt_L = Meta_L
1861 keysym Alt_R = Meta_R
1866 keysym Mode_switch = NoSymbol
1868 keysym Meta_R = Mode_switch
1869 add mod2 = Mode_switch
1872 *** HP/UX: "Cannot find callback list" messages from dialog boxes in
1873 Emacs built with Motif.
1875 This problem resulted from a bug in GCC 2.4.5. Newer GCC versions
1876 such as 2.7.0 fix the problem.
1878 *** HP/UX: Emacs does not recognize the AltGr key.
1880 To fix this, set up a file ~/.dt/sessions/sessionetc with executable
1881 rights, containing this text:
1883 --------------------------------
1884 xmodmap 2> /dev/null - << EOF
1885 keysym Alt_L = Meta_L
1886 keysym Alt_R = Meta_R
1891 keysym Mode_switch = NoSymbol
1893 keysym Meta_R = Mode_switch
1894 add mod2 = Mode_switch
1896 --------------------------------
1898 *** HP/UX 11.0: Emacs makes HP/UX 11.0 crash.
1900 This is a bug in HPUX; HPUX patch PHKL_16260 is said to fix it.
1904 *** AIX: Trouble using ptys.
1906 People often install the pty devices on AIX incorrectly.
1907 Use `smit pty' to reinstall them properly.
1909 *** AIXterm: Your Delete key sends a Backspace to the terminal.
1911 The solution is to include in your .Xdefaults the lines:
1913 *aixterm.Translations: #override <Key>BackSpace: string(0x7f)
1914 aixterm*ttyModes: erase ^?
1916 This makes your Backspace key send DEL (ASCII 127).
1918 *** AIX: If linking fails because libXbsd isn't found, check if you
1919 are compiling with the system's `cc' and CFLAGS containing `-O5'. If
1920 so, you have hit a compiler bug. Please make sure to re-configure
1921 Emacs so that it isn't compiled with `-O5'.
1923 *** AIX 4.3.x or 4.4: Compiling fails.
1925 This could happen if you use /bin/c89 as your compiler, instead of
1926 the default `cc'. /bin/c89 treats certain warnings, such as benign
1927 redefinitions of macros, as errors, and fails the build. A solution
1928 is to use the default compiler `cc'.
1930 *** AIX 4: Some programs fail when run in a Shell buffer
1931 with an error message like No terminfo entry for "unknown".
1933 On AIX, many terminal type definitions are not installed by default.
1934 `unknown' is one of them. Install the "Special Generic Terminal
1935 Definitions" to make them defined.
1939 We list bugs in current versions here. Solaris 2.x and 4.x are covered in the
1940 section on legacy systems.
1942 *** On Solaris, C-x doesn't get through to Emacs when you use the console.
1944 This is a Solaris feature (at least on Intel x86 cpus). Type C-r
1945 C-r C-t, to toggle whether C-x gets through to Emacs.
1947 *** Problem with remote X server on Suns.
1949 On a Sun, running Emacs on one machine with the X server on another
1950 may not work if you have used the unshared system libraries. This
1951 is because the unshared libraries fail to use YP for host name lookup.
1952 As a result, the host name you specify may not be recognized.
1954 *** Solaris 2,6: Emacs crashes with SIGBUS or SIGSEGV on Solaris after you delete a frame.
1956 We suspect that this is a bug in the X libraries provided by
1957 Sun. There is a report that one of these patches fixes the bug and
1958 makes the problem stop:
1960 105216-01 105393-01 105518-01 105621-01 105665-01 105615-02 105216-02
1961 105667-01 105401-08 105615-03 105621-02 105686-02 105736-01 105755-03
1962 106033-01 105379-01 105786-01 105181-04 105379-03 105786-04 105845-01
1963 105284-05 105669-02 105837-01 105837-02 105558-01 106125-02 105407-01
1965 Another person using a newer system (kernel patch level Generic_105181-06)
1966 suspects that the bug was fixed by one of these more recent patches:
1968 106040-07 SunOS 5.6: X Input & Output Method patch
1969 106222-01 OpenWindows 3.6: filemgr (ff.core) fixes
1970 105284-12 Motif 1.2.7: sparc Runtime library patch
1972 *** Solaris 7 or 8: Emacs reports a BadAtom error (from X)
1974 This happens when Emacs was built on some other version of Solaris.
1975 Rebuild it on Solaris 8.
1977 *** When using M-x dbx with the SparcWorks debugger, the `up' and `down'
1978 commands do not move the arrow in Emacs.
1980 You can fix this by adding the following line to `~/.dbxinit':
1982 dbxenv output_short_file_name off
1984 *** On Solaris, CTRL-t is ignored by Emacs when you use
1985 the fr.ISO-8859-15 locale (and maybe other related locales).
1987 You can fix this by editing the file:
1989 /usr/openwin/lib/locale/iso8859-15/Compose
1991 Near the bottom there is a line that reads:
1993 Ctrl<t> <quotedbl> <Y> : "\276" threequarters
1997 Ctrl<T> <quotedbl> <Y> : "\276" threequarters
1999 Note the lower case <t>. Changing this line should make C-t work.
2001 *** On Solaris, Emacs fails to set menu-bar-update-hook on startup, with error
2002 "Error in menu-bar-update-hook: (error Point before start of properties)".
2003 This seems to be a GCC optimization bug that occurs for GCC 4.1.2 (-g
2004 and -g -O2) and GCC 4.2.3 (-g -O and -g -O2). You can fix this by
2005 compiling with GCC 4.2.3 or CC 5.7, with no optimizations.
2009 *** Irix 6.5: Emacs crashes on the SGI R10K, when compiled with GCC.
2011 This seems to be fixed in GCC 2.95.
2013 *** Irix: Trouble using ptys, or running out of ptys.
2015 The program mkpts (which may be in `/usr/adm' or `/usr/sbin') needs to
2016 be set-UID to root, or non-root programs like Emacs will not be able
2017 to allocate ptys reliably.
2019 * Runtime problems specific to MS-Windows
2021 ** PATH can contain unexpanded environment variables
2023 Old releases of TCC (version 9) and 4NT (up to version 8) do not correctly
2024 expand App Paths entries of type REG_EXPAND_SZ. When Emacs is run from TCC
2025 and such an entry exists for emacs.exe, exec-path will contain the
2026 unexpanded entry. This has been fixed in TCC 10. For more information,
2029 ** Setting w32-pass-rwindow-to-system and w32-pass-lwindow-to-system to nil
2030 does not prevent the Start menu from popping up when the left or right
2031 ``Windows'' key is pressed.
2033 This was reported to happen when XKeymacs is installed. At least with
2034 XKeymacs Version 3.47, deactivating XKeymacs when Emacs is active is
2035 not enough to avoid its messing with the keyboard input. Exiting
2036 XKeymacs completely is reported to solve the problem.
2038 ** Windows 95 and networking.
2040 To support server sockets, Emacs 22.1 loads ws2_32.dll. If this file
2041 is missing, all Emacs networking features are disabled.
2043 Old versions of Windows 95 may not have the required DLL. To use
2044 Emacs' networking features on Windows 95, you must install the
2045 "Windows Socket 2" update available from MicroSoft's support Web.
2047 ** Emacs exits with "X protocol error" when run with an X server for MS-Windows.
2049 A certain X server for Windows had a bug which caused this.
2050 Supposedly the newer 32-bit version of this server doesn't have the
2053 ** Emacs crashes when opening a file with a UNC path and rails-mode is loaded.
2055 Loading rails-mode seems to interfere with UNC path handling. This has been
2056 reported as a bug against both Emacs and rails-mode, so look for an updated
2057 rails-mode that avoids this crash, or avoid using UNC paths if using
2060 ** Known problems with the MS-Windows port of Emacs 22.3
2062 M-x term does not work on MS-Windows. TTY emulation on Windows is
2063 undocumented, and programs such as stty which are used on posix platforms
2064 to control tty emulation do not exist for native windows terminals.
2066 Using create-fontset-from-ascii-font or the --font startup parameter
2067 with a Chinese, Japanese or Korean font leads to display problems.
2068 Use a Latin-only font as your default font. If you want control over
2069 which font is used to display Chinese, Japanese or Korean character,
2070 use create-fontset-from-fontset-spec to define a fontset.
2072 Frames are not refreshed while the File or Font dialog or a pop-up menu
2073 is displayed. This also means help text for pop-up menus is not
2074 displayed at all. This is because message handling under Windows is
2075 synchronous, so we cannot handle repaint (or any other) messages while
2076 waiting for a system function to return the result of the dialog or
2077 pop-up menu interaction.
2079 Windows 95 and Windows NT up to version 4.0 do not support help text
2080 for menus. Help text is only available in later versions of Windows.
2082 When "ClearType" method is selected as the "method to smooth edges of
2083 screen fonts" (in Display Properties, Appearance tab, under
2084 "Effects"), there are various problems related to display of
2085 characters: Bold fonts can be hard to read, small portions of some
2086 characters could appear chopped, etc. This happens because, under
2087 ClearType, characters are drawn outside their advertised bounding box.
2088 Emacs 21 disabled the use of ClearType, whereas Emacs 22 allows it and
2089 has some code to enlarge the width of the bounding box. Apparently,
2090 this display feature needs more changes to get it 100% right. A
2091 workaround is to disable ClearType.
2093 There are problems with display if mouse-tracking is enabled and the
2094 mouse is moved off a frame, over another frame then back over the first
2095 frame. A workaround is to click the left mouse button inside the frame
2096 after moving back into it.
2098 Some minor flickering still persists during mouse-tracking, although
2099 not as severely as in 21.1.
2101 An inactive cursor remains in an active window after the Windows
2102 Manager driven switch of the focus, until a key is pressed.
2104 Windows input methods are not recognized by Emacs. However, some
2105 of these input methods cause the keyboard to send characters encoded
2106 in the appropriate coding system (e.g., ISO 8859-1 for Latin-1
2107 characters, ISO 8859-8 for Hebrew characters, etc.). To make these
2108 input methods work with Emacs, set the keyboard coding system to the
2109 appropriate value after you activate the Windows input method. For
2110 example, if you activate the Hebrew input method, type this:
2112 C-x RET k hebrew-iso-8bit RET
2114 (Emacs ought to recognize the Windows language-change event and set up
2115 the appropriate keyboard encoding automatically, but it doesn't do
2116 that yet.) In addition, to use these Windows input methods, you
2117 should set your "Language for non-Unicode programs" (on Windows XP,
2118 this is on the Advanced tab of Regional Settings) to the language of
2121 To bind keys that produce non-ASCII characters with modifiers, you
2122 must specify raw byte codes. For instance, if you want to bind
2123 META-a-grave to a command, you need to specify this in your `~/.emacs':
2125 (global-set-key [?\M-\340] ...)
2127 The above example is for the Latin-1 environment where the byte code
2128 of the encoded a-grave is 340 octal. For other environments, use the
2129 encoding appropriate to that environment.
2131 The %b specifier for format-time-string does not produce abbreviated
2132 month names with consistent widths for some locales on some versions
2133 of Windows. This is caused by a deficiency in the underlying system
2136 The function set-time-zone-rule gives incorrect results for many
2137 non-US timezones. This is due to over-simplistic handling of
2138 daylight savings switchovers by the Windows libraries.
2140 Files larger than 4GB cause overflow in the size (represented as a
2141 32-bit integer) reported by `file-attributes'. This affects Dired as
2142 well, since the Windows port uses a Lisp emulation of `ls' that relies
2143 on `file-attributes'.
2145 Sound playing is not supported with the `:data DATA' key-value pair.
2146 You _must_ use the `:file FILE' method.
2148 ** Typing Alt-Shift has strange effects on MS-Windows.
2150 This combination of keys is a command to change keyboard layout. If
2151 you proceed to type another non-modifier key before you let go of Alt
2152 and Shift, the Alt and Shift act as modifiers in the usual way. A
2153 more permanent work around is to change it to another key combination,
2154 or disable it in the "Regional and Language Options" applet of the
2155 Control Panel. (The exact sequence of mouse clicks in the "Regional
2156 and Language Options" applet needed to find the key combination that
2157 changes the keyboard layout depends on your Windows version; for XP,
2158 in the Languages tab, click "Details" and then "Key Settings".)
2160 ** Interrupting Cygwin port of Bash from Emacs doesn't work.
2162 Cygwin 1.x builds of the ported Bash cannot be interrupted from the
2163 MS-Windows version of Emacs. This is due to some change in the Bash
2164 port or in the Cygwin library which apparently make Bash ignore the
2165 keyboard interrupt event sent by Emacs to Bash. (Older Cygwin ports
2166 of Bash, up to b20.1, did receive SIGINT from Emacs.)
2168 ** Accessing remote files with ange-ftp hangs the MS-Windows version of Emacs.
2170 If the FTP client is the Cygwin port of GNU `ftp', this appears to be
2171 due to some bug in the Cygwin DLL or some incompatibility between it
2172 and the implementation of asynchronous subprocesses in the Windows
2173 port of Emacs. Specifically, some parts of the FTP server responses
2174 are not flushed out, apparently due to buffering issues, which
2177 The solution is to downgrade to an older version of the Cygwin DLL
2178 (version 1.3.2 was reported to solve the problem), or use the stock
2179 Windows FTP client, usually found in the `C:\WINDOWS' or 'C:\WINNT'
2180 directory. To force ange-ftp use the stock Windows client, set the
2181 variable `ange-ftp-ftp-program-name' to the absolute file name of the
2182 client's executable. For example:
2184 (setq ange-ftp-ftp-program-name "c:/windows/ftp.exe")
2186 If you want to stick with the Cygwin FTP client, you can work around
2187 this problem by putting this in your `.emacs' file:
2189 (setq ange-ftp-ftp-program-args '("-i" "-n" "-g" "-v" "--prompt" "")
2191 ** lpr commands don't work on MS-Windows with some cheap printers.
2193 This problem may also strike other platforms, but the solution is
2194 likely to be a global one, and not Emacs specific.
2196 Many cheap inkjet, and even some cheap laser printers, do not
2197 print plain text anymore, they will only print through graphical
2198 printer drivers. A workaround on MS-Windows is to use Windows' basic
2199 built in editor to print (this is possibly the only useful purpose it
2202 (setq printer-name "") ;; notepad takes the default
2203 (setq lpr-command "notepad") ;; notepad
2204 (setq lpr-switches nil) ;; not needed
2205 (setq lpr-printer-switch "/P") ;; run notepad as batch printer
2207 ** Antivirus software interacts badly with the MS-Windows version of Emacs.
2209 The usual manifestation of these problems is that subprocesses don't
2210 work or even wedge the entire system. In particular, "M-x shell RET"
2211 was reported to fail to work. But other commands also sometimes don't
2212 work when an antivirus package is installed.
2214 The solution is to switch the antivirus software to a less aggressive
2215 mode (e.g., disable the ``auto-protect'' feature), or even uninstall
2216 or disable it entirely.
2218 ** Pressing the mouse button on MS-Windows does not give a mouse-2 event.
2220 This is usually a problem with the mouse driver. Because most Windows
2221 programs do not do anything useful with the middle mouse button, many
2222 mouse drivers allow you to define the wheel press to do something
2223 different. Some drivers do not even have the option to generate a
2224 middle button press. In such cases, setting the wheel press to
2225 "scroll" sometimes works if you press the button twice. Trying a
2226 generic mouse driver might help.
2228 ** Scrolling the mouse wheel on MS-Windows always scrolls the top window.
2230 This is another common problem with mouse drivers. Instead of
2231 generating scroll events, some mouse drivers try to fake scroll bar
2232 movement. But they are not intelligent enough to handle multiple
2233 scroll bars within a frame. Trying a generic mouse driver might help.
2235 ** Mail sent through Microsoft Exchange in some encodings appears to be
2236 mangled and is not seen correctly in Rmail or Gnus. We don't know
2237 exactly what happens, but it isn't an Emacs problem in cases we've
2240 ** On MS-Windows, you cannot use the right-hand ALT key and the left-hand
2241 CTRL key together to type a Control-Meta character.
2243 This is a consequence of a misfeature beyond Emacs's control.
2245 Under Windows, the AltGr key on international keyboards generates key
2246 events with the modifiers Right-Alt and Left-Ctrl. Since Emacs cannot
2247 distinguish AltGr from an explicit Right-Alt and Left-Ctrl
2248 combination, whenever it sees Right-Alt and Left-Ctrl it assumes that
2249 AltGr has been pressed. The variable `w32-recognize-altgr' can be set
2250 to nil to tell Emacs that AltGr is really Ctrl and Alt.
2252 ** Under some X-servers running on MS-Windows, Emacs' display is incorrect.
2254 The symptoms are that Emacs does not completely erase blank areas of the
2255 screen during scrolling or some other screen operations (e.g., selective
2256 display or when killing a region). M-x recenter will cause the screen
2257 to be completely redisplayed and the "extra" characters will disappear.
2259 This is known to occur under Exceed 6, and possibly earlier versions
2260 as well; it is reportedly solved in version 6.2.0.16 and later. The
2261 problem lies in the X-server settings.
2263 There are reports that you can solve the problem with Exceed by
2264 running `Xconfig' from within NT, choosing "X selection", then
2265 un-checking the boxes "auto-copy X selection" and "auto-paste to X
2268 Of this does not work, please inform bug-gnu-emacs@gnu.org. Then
2269 please call support for your X-server and see if you can get a fix.
2270 If you do, please send it to bug-gnu-emacs@gnu.org so we can list it
2273 * Build-time problems
2277 *** The `configure' script doesn't find the jpeg library.
2279 There are reports that this happens on some systems because the linker
2280 by default only looks for shared libraries, but jpeg distribution by
2281 default only installs a nonshared version of the library, `libjpeg.a'.
2283 If this is the problem, you can configure the jpeg library with the
2284 `--enable-shared' option and then rebuild libjpeg. This produces a
2285 shared version of libjpeg, which you need to install. Finally, rerun
2286 the Emacs configure script, which should now find the jpeg library.
2287 Alternatively, modify the generated src/Makefile to link the .a file
2288 explicitly, and edit src/config.h to define HAVE_JPEG.
2290 *** `configure' warns ``accepted by the compiler, rejected by the preprocessor''.
2292 This indicates a mismatch between the C compiler and preprocessor that
2293 configure is using. For example, on Solaris 10 trying to use
2294 CC=/opt/SUNWspro/bin/cc (the Sun Studio compiler) together with
2295 CPP=/usr/ccs/lib/cpp can result in errors of this form (you may also
2296 see the error ``"/usr/include/sys/isa_defs.h", line 500: undefined control'').
2298 The solution is to tell configure to use the correct C preprocessor
2299 for your C compiler (CPP="/opt/SUNWspro/bin/cc -E" in the above
2304 *** Building Emacs over NFS fails with ``Text file busy''.
2306 This was reported to happen when building Emacs on a GNU/Linux system
2307 (Red Hat Linux 6.2) using a build directory automounted from Solaris
2308 (SunOS 5.6) file server, but it might not be limited to that
2309 configuration alone. Presumably, the NFS server doesn't commit the
2310 files' data to disk quickly enough, and the Emacs executable file is
2311 left ``busy'' for several seconds after Emacs has finished dumping
2312 itself. This causes the subsequent commands which invoke the dumped
2313 Emacs executable to fail with the above message.
2315 In some of these cases, a time skew between the NFS server and the
2316 machine where Emacs is built is detected and reported by GNU Make
2317 (it says that some of the files have modification time in the future).
2318 This might be a symptom of NFS-related problems.
2320 If the NFS server runs on Solaris, apply the Solaris patch 105379-05
2321 (Sunos 5.6: /kernel/misc/nfssrv patch). If that doesn't work, or if
2322 you have a different version of the OS or the NFS server, you can
2323 force the NFS server to use 1KB blocks, which was reported to fix the
2324 problem albeit at a price of slowing down file I/O. You can force 1KB
2325 blocks by specifying the "-o rsize=1024,wsize=1024" options to the
2326 `mount' command, or by adding ",rsize=1024,wsize=1024" to the mount
2327 options in the appropriate system configuration file, such as
2330 Alternatively, when Make fails due to this problem, you could wait for
2331 a few seconds and then invoke Make again. In one particular case,
2332 waiting for 10 or more seconds between the two Make invocations seemed
2333 to work around the problem.
2335 Similar problems can happen if your machine NFS-mounts a directory
2336 onto itself. Suppose the Emacs sources live in `/usr/local/src' and
2337 you are working on the host called `marvin'. Then an entry in the
2338 `/etc/fstab' file like the following is asking for trouble:
2340 marvin:/usr/local/src /usr/local/src ...options.omitted...
2342 The solution is to remove this line from `etc/fstab'.
2344 *** Building a 32-bit executable on a 64-bit GNU/Linux architecture.
2346 First ensure that the necessary 32-bit system libraries and include
2347 files are installed. Then use:
2349 env CC="gcc -m32" ./configure --build=i386-linux-gnu \
2350 --x-libraries=/usr/X11R6/lib
2352 (using the location of the 32-bit X libraries on your system).
2354 *** Building the Cygwin port for MS-Windows can fail with some GCC versions
2356 Building Emacs 22 with Cygwin builds of GCC 3.4.4-1 and 3.4.4-2 is
2357 reported to either fail or cause Emacs to segfault at run time. In
2358 addition, the Cygwin GCC 3.4.4-2 has problems with generating debug
2359 info. Cygwin users are advised not to use these versions of GCC for
2360 compiling Emacs. GCC versions 4.0.3, 4.0.4, 4.1.1, and 4.1.2
2361 reportedly build a working Cygwin binary of Emacs, so we recommend
2362 these GCC versions. Note that these versions of GCC, 4.0.3, 4.0.4,
2363 4.1.1, and 4.1.2, are currently the _only_ versions known to succeed
2364 in building Emacs (as of v22.1).
2366 *** Building the native MS-Windows port fails due to unresolved externals
2368 The linker error messages look like this:
2370 oo-spd/i386/ctags.o:ctags.c:(.text+0x156e): undefined reference to `_imp__re_set_syntax'
2371 collect2: ld returned 1 exit status
2373 This happens because GCC finds an incompatible header regex.h
2374 somewhere on the include path, before the version of regex.h supplied
2375 with Emacs. One such incompatible version of regex.h is part of the
2376 GnuWin32 Regex package.
2378 The solution is to remove the incompatible regex.h from the include
2379 path, when compiling Emacs. Alternatively, re-run the configure.bat
2380 script with the "-isystem C:/GnuWin32/include" switch (adapt for your
2381 system's place where you keep the GnuWin32 include files) -- this will
2382 cause the compiler to search headers in the directories specified by
2383 the Emacs Makefile _before_ it looks in the GnuWin32 include
2386 *** Building the native MS-Windows port with Cygwin GCC can fail.
2388 Emacs may not build using some Cygwin builds of GCC, such as Cygwin
2389 version 1.1.8, using the default configure settings. It appears to be
2390 necessary to specify the -mwin32 flag when compiling, and define
2391 __MSVCRT__, like so:
2393 configure --with-gcc --cflags -mwin32 --cflags -D__MSVCRT__
2395 *** Building the MS-Windows port fails with a CreateProcess failure.
2397 Some versions of mingw32 make on some versions of Windows do not seem
2398 to detect the shell correctly. Try "make SHELL=cmd.exe", or if that
2399 fails, try running make from Cygwin bash instead.
2401 *** Building `ctags' for MS-Windows with the MinGW port of GCC fails.
2403 This might happen due to a bug in the MinGW header assert.h, which
2404 defines the `assert' macro with a trailing semi-colon. The following
2405 patch to assert.h should solve this:
2407 *** include/assert.h.orig Sun Nov 7 02:41:36 1999
2408 --- include/assert.h Mon Jan 29 11:49:10 2001
2412 * If not debugging, assert does nothing.
2414 ! #define assert(x) ((void)0);
2416 #else /* debugging enabled */
2420 * If not debugging, assert does nothing.
2422 ! #define assert(x) ((void)0)
2424 #else /* debugging enabled */
2427 *** Building the MS-Windows port with Visual Studio 2005 fails.
2429 Microsoft no longer ships the single threaded version of the C library
2430 with their compiler, and the multithreaded static library is missing
2431 some functions that Microsoft have deemed non-threadsafe. The
2432 dynamically linked C library has all the functions, but there is a
2433 conflict between the versions of malloc in the DLL and in Emacs, which
2434 is not resolvable due to the way Windows does dynamic linking.
2436 We recommend the use of the MinGW port of GCC for compiling Emacs, as
2437 not only does it not suffer these problems, but it is also Free
2438 software like Emacs.
2440 *** Building the MS-Windows port with Visual Studio fails compiling emacs.rc
2442 If the build fails with the following message then the problem
2443 described here most likely applies:
2445 ../nt/emacs.rc(1) : error RC2176 : old DIB in icons\emacs.ico; pass it
2448 The Emacs icon contains a high resolution PNG icon for Vista, which is
2449 not recognized by older versions of the resource compiler. There are
2450 several workarounds for this problem:
2451 1. Use Free MinGW tools to compile, which do not have this problem.
2452 2. Install the latest Windows SDK.
2453 3. Replace emacs.ico with an older or edited icon.
2457 *** Building Emacs with a system compiler fails to link because of an
2458 undefined symbol such as __eprintf which does not appear in Emacs.
2460 This can happen if some of the libraries linked into Emacs were built
2461 with GCC, but Emacs itself is being linked with a compiler other than
2462 GCC. Object files compiled with GCC might need some helper functions
2463 from libgcc.a, the library which comes with GCC, but the system
2464 compiler does not instruct the linker to search libgcc.a during the
2467 A solution is to link with GCC, like this:
2471 Since the .o object files already exist, this will not recompile Emacs
2472 with GCC, but just restart by trying again to link temacs.
2474 *** Sun with acc: Link failure when using acc on a Sun.
2476 To use acc, you need additional options just before the libraries, such as
2478 /usr/lang/SC2.0.1/values-Xt.o -L/usr/lang/SC2.0.1/cg87 -L/usr/lang/SC2.0.1
2480 and you need to add -lansi just before -lc.
2482 The precise file names depend on the compiler version, so we
2483 cannot easily arrange to supply them.
2485 *** Linking says that the functions insque and remque are undefined.
2487 Change oldXMenu/Makefile by adding insque.o to the variable OBJS.
2489 *** `tparam' reported as a multiply-defined symbol when linking with ncurses.
2491 This problem results from an incompatible change in ncurses, in
2492 version 1.9.9e approximately. This version is unable to provide a
2493 definition of tparm without also defining tparam. This is also
2494 incompatible with Terminfo; as a result, the Emacs Terminfo support
2495 does not work with this version of ncurses.
2497 The fix is to install a newer version of ncurses, such as version 4.2.
2501 Bootstrapping (compiling the .el files) is normally only necessary
2502 with CVS builds, since the .elc files are pre-compiled in releases.
2504 *** "No rule to make target" with Ubuntu 8.04 make 3.81-3build1
2506 Compiling the lisp files fails at random places, complaining:
2507 "No rule to make target `/path/to/some/lisp.elc'".
2508 The causes of this problem are not understood. Using GNU make 3.81 compiled
2509 from source, rather than the Ubuntu version, worked. See Bug#327,821.
2513 *** Linux: Segfault during `make bootstrap' under certain recent versions of the Linux kernel.
2515 With certain recent Linux kernels (like the one of Red Hat Fedora Core
2516 1 and newer), the new "Exec-shield" functionality is enabled by default, which
2517 creates a different memory layout that breaks the emacs dumper. Emacs tries
2518 to handle this at build time, but if the workaround used fails, these
2519 instructions can be useful.
2520 The work-around explained here is not enough on Fedora Core 4 (and possible
2521 newer). Read the next item.
2523 Configure can overcome the problem of exec-shield if the architecture is
2524 x86 and the program setarch is present. On other architectures no
2525 workaround is known.
2527 You can check the Exec-shield state like this:
2529 cat /proc/sys/kernel/exec-shield
2531 It returns non-zero when Exec-shield is enabled, 0 otherwise. Please
2532 read your system documentation for more details on Exec-shield and
2533 associated commands. Exec-shield can be turned off with this command:
2535 echo "0" > /proc/sys/kernel/exec-shield
2537 When Exec-shield is enabled, building Emacs will segfault during the
2538 execution of this command:
2540 ./temacs --batch --load loadup [dump|bootstrap]
2542 To work around this problem, it is necessary to temporarily disable
2543 Exec-shield while building Emacs, or, on x86, by using the `setarch'
2544 command when running temacs like this:
2546 setarch i386 ./temacs --batch --load loadup [dump|bootstrap]
2549 *** Fedora Core 4 GNU/Linux: Segfault during dumping.
2551 In addition to exec-shield explained above "Linux: Segfault during
2552 `make bootstrap' under certain recent versions of the Linux kernel"
2553 item, Linux kernel shipped with Fedora Core 4 randomizes the virtual
2554 address space of a process. As the result dumping may fail even if
2555 you turn off exec-shield. In this case, use the -R option to the setarch
2558 setarch i386 -R ./temacs --batch --load loadup [dump|bootstrap]
2562 setarch i386 -R make bootstrap
2564 *** Fatal signal in the command temacs -l loadup inc dump.
2566 This command is the final stage of building Emacs. It is run by the
2567 Makefile in the src subdirectory.
2569 It has been known to get fatal errors due to insufficient swapping
2570 space available on the machine.
2572 On 68000s, it has also happened because of bugs in the
2573 subroutine `alloca'. Verify that `alloca' works right, even
2574 for large blocks (many pages).
2576 *** test-distrib says that the distribution has been clobbered.
2577 *** or, temacs prints "Command key out of range 0-127".
2578 *** or, temacs runs and dumps emacs, but emacs totally fails to work.
2579 *** or, temacs gets errors dumping emacs.
2581 This can be because the .elc files have been garbled. Do not be
2582 fooled by the fact that most of a .elc file is text: these are
2583 binary files and can contain all 256 byte values.
2585 In particular `shar' cannot be used for transmitting GNU Emacs.
2586 It typically truncates "lines". What appear to be "lines" in
2587 a binary file can of course be of any length. Even once `shar'
2588 itself is made to work correctly, `sh' discards null characters
2589 when unpacking the shell archive.
2591 I have also seen character \177 changed into \377. I do not know
2592 what transfer means caused this problem. Various network
2593 file transfer programs are suspected of clobbering the high bit.
2595 If you have a copy of Emacs that has been damaged in its
2596 nonprinting characters, you can fix them:
2598 1) Record the names of all the .elc files.
2599 2) Delete all the .elc files.
2600 3) Recompile alloc.c with a value of PURESIZE twice as large.
2601 (See puresize.h.) You might as well save the old alloc.o.
2602 4) Remake emacs. It should work now.
2603 5) Running emacs, do Meta-x byte-compile-file repeatedly
2604 to recreate all the .elc files that used to exist.
2605 You may need to increase the value of the variable
2606 max-lisp-eval-depth to succeed in running the compiler interpreted
2607 on certain .el files. 400 was sufficient as of last report.
2608 6) Reinstall the old alloc.o (undoing changes to alloc.c if any)
2610 7) Remake emacs. It should work now, with valid .elc files.
2612 *** temacs prints "Pure Lisp storage exhausted".
2614 This means that the Lisp code loaded from the .elc and .el
2615 files during temacs -l loadup inc dump took up more
2616 space than was allocated.
2618 This could be caused by
2619 1) adding code to the preloaded Lisp files
2620 2) adding more preloaded files in loadup.el
2621 3) having a site-init.el or site-load.el which loads files.
2622 Note that ANY site-init.el or site-load.el is nonstandard;
2623 if you have received Emacs from some other site
2624 and it contains a site-init.el or site-load.el file, consider
2626 4) getting the wrong .el or .elc files
2627 (not from the directory you expected).
2628 5) deleting some .elc files that are supposed to exist.
2629 This would cause the source files (.el files) to be
2630 loaded instead. They take up more room, so you lose.
2631 6) a bug in the Emacs distribution which underestimates
2634 If the need for more space is legitimate, change the definition
2635 of PURESIZE in puresize.h.
2637 But in some of the cases listed above, this problem is a consequence
2638 of something else that is wrong. Be sure to check and fix the real
2641 *** Linux: Emacs crashes when dumping itself on Mac PPC running Yellow Dog GNU/Linux.
2643 The crashes happen inside the function Fmake_symbol; here's a typical
2644 C backtrace printed by GDB:
2646 0x190c0c0 in Fmake_symbol ()
2648 #0 0x190c0c0 in Fmake_symbol ()
2649 #1 0x1942ca4 in init_obarray ()
2650 #2 0x18b3500 in main ()
2651 #3 0x114371c in __libc_start_main (argc=5, argv=0x7ffff5b4, envp=0x7ffff5cc,
2653 This could happen because GCC version 2.95 and later changed the base
2654 of the load address to 0x10000000. Emacs needs to be told about this,
2655 but we currently cannot do that automatically, because that breaks
2656 other versions of GNU/Linux on the MacPPC. Until we find a way to
2657 distinguish between the Yellow Dog and the other varieties of
2658 GNU/Linux systems on the PPC, you will have to manually uncomment the
2659 following section near the end of the file src/m/macppc.h in the Emacs
2662 #if 0 /* This breaks things on PPC GNU/Linux except for Yellowdog,
2663 even with identical GCC, as, ld. Let's take it out until we
2664 know what's really going on here. */
2665 /* GCC 2.95 and newer on GNU/Linux PPC changed the load address to
2667 #if defined __linux__
2668 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 95)
2669 #define DATA_SEG_BITS 0x10000000
2674 Remove the "#if 0" and "#endif" directives which surround this, save
2675 the file, and then reconfigure and rebuild Emacs. The dumping process
2678 *** OpenBSD 4.0 macppc: Segfault during dumping.
2680 The build aborts with signal 11 when the command `./temacs --batch
2681 --load loadup bootstrap' tries to load files.el. A workaround seems
2682 to be to reduce the level of compiler optimization used during the
2683 build (from -O2 to -O1). It is possible this is an OpenBSD
2684 GCC problem specific to the macppc architecture, possibly only
2685 occurring with older versions of GCC (e.g. 3.3.5).
2687 *** openSUSE 10.3: Segfault in bcopy during dumping.
2689 This is due to a bug in the bcopy implementation in openSUSE 10.3.
2690 It is/will be fixed in an openSUSE update.
2694 *** Installing Emacs gets an error running `install-info'.
2696 You need to install a recent version of Texinfo; that package
2697 supplies the `install-info' command.
2699 *** Installing to a directory with spaces in the name fails.
2701 For example, if you call configure with a directory-related option
2702 with spaces in the value, eg --enable-locallisppath='/path/with\ spaces'.
2703 Using directory paths with spaces is not supported at this time: you
2704 must re-configure without using spaces.
2706 *** Installing to a directory with non-ASCII characters in the name fails.
2708 Installation may fail, or the Emacs executable may not start
2709 correctly, if a directory name containing non-ASCII characters is used
2710 as a `configure' argument (e.g. `--prefix'). The problem can also
2711 occur if a non-ASCII directory is specified in the EMACSLOADPATH
2714 *** On Solaris, use GNU Make when installing an out-of-tree build
2716 The Emacs configuration process allows you to configure the
2717 build environment so that you can build emacs in a directory
2718 outside of the distribution tree. When installing Emacs from an
2719 out-of-tree build directory on Solaris, you may need to use GNU
2720 make. The make programs bundled with Solaris support the VPATH
2721 macro but use it differently from the way the VPATH macro is
2722 used by GNU make. The differences will cause the "make install"
2723 step to fail, leaving you with an incomplete emacs
2724 installation. GNU make is available in /usr/sfw/bin on Solaris
2725 10 and can be installed as /opt/sfw/bin/gmake from the Solaris 9
2726 Software Companion CDROM.
2728 The problems due to the VPATH processing differences affect only
2729 out of tree builds so, if you are on a Solaris installation
2730 without GNU make, you can install Emacs completely by installing
2731 from a build environment using the original emacs distribution tree.
2735 *** Emacs binary is not in executable format, and cannot be run.
2737 This was reported to happen when Emacs is built in a directory mounted
2738 via NFS, for some combinations of NFS client and NFS server.
2739 Usually, the file `emacs' produced in these cases is full of
2740 binary null characters, and the `file' utility says:
2742 emacs: ASCII text, with no line terminators
2744 We don't know what exactly causes this failure. A work-around is to
2745 build Emacs in a directory on a local disk.
2747 *** The dumped Emacs crashes when run, trying to write pure data.
2749 Two causes have been seen for such problems.
2751 1) On a system where getpagesize is not a system call, it is defined
2752 as a macro. If the definition (in both unexec.c and malloc.c) is wrong,
2753 it can cause problems like this. You might be able to find the correct
2754 value in the man page for a.out (5).
2756 2) Some systems allocate variables declared static among the
2757 initialized variables. Emacs makes all initialized variables in most
2758 of its files pure after dumping, but the variables declared static and
2759 not initialized are not supposed to be pure. On these systems you
2760 may need to add "#define static" to the m- or the s- file.
2762 * Runtime problems on legacy systems
2764 This section covers bugs reported on very old hardware or software.
2765 If you are using hardware and an operating system shipped after 2000,
2766 it is unlikely you will see any of these.
2768 *** Sunos 5.3: Subprocesses remain, hanging but not zombies.
2770 A bug in Sunos 5.3 causes Emacs subprocesses to remain after Emacs
2771 exits. Sun patch # 101415-02 is part of the fix for this, but it only
2772 applies to ptys, and doesn't fix the problem with subprocesses
2773 communicating through pipes.
2777 **** OPENSTEP 4.2: Compiling syntax.c with gcc 2.7.2.1 fails.
2779 The compiler was reported to crash while compiling syntax.c with the
2782 cc: Internal compiler error: program cc1obj got fatal signal 11
2784 To work around this, replace the macros UPDATE_SYNTAX_TABLE_FORWARD,
2785 INC_BOTH, and INC_FROM with functions. To this end, first define 3
2786 functions, one each for every macro. Here's an example:
2788 static int update_syntax_table_forward(int from)
2790 return(UPDATE_SYNTAX_TABLE_FORWARD(from));
2791 }/*update_syntax_table_forward*/
2793 Then replace all references to UPDATE_SYNTAX_TABLE_FORWARD in syntax.c
2794 with a call to the function update_syntax_table_forward.
2798 **** Strange results from format %d in a few cases, on a Sun.
2800 Sun compiler version SC3.0 has been found to miscompile part of
2801 editfns.c. The workaround is to compile with some other compiler such
2804 **** On Solaris, Emacs dumps core if lisp-complete-symbol is called.
2806 If you compile Emacs with the -fast or -xO4 option with version 3.0.2
2807 of the Sun C compiler, Emacs dumps core when lisp-complete-symbol is
2808 called. The problem does not happen if you compile with GCC.
2810 **** On Solaris, Emacs crashes if you use (display-time).
2812 This can happen if you configure Emacs without specifying the precise
2813 version of Solaris that you are using.
2815 **** Solaris 2.x: GCC complains "64 bit integer types not supported".
2817 This suggests that GCC is not installed correctly. Most likely you
2818 are using GCC 2.7.2.3 (or earlier) on Solaris 2.6 (or later); this
2819 does not work without patching. To run GCC 2.7.2.3 on Solaris 2.6 or
2820 later, you must patch fixinc.svr4 and reinstall GCC from scratch as
2821 described in the Solaris FAQ
2822 <http://www.wins.uva.nl/pub/solaris/solaris2.html>. A better fix is
2823 to upgrade to GCC 2.8.1 or later.
2825 **** Solaris 2.7: Building Emacs with WorkShop Compilers 5.0 98/12/15
2826 C 5.0 failed, apparently with non-default CFLAGS, most probably due to
2827 compiler bugs. Using Sun Solaris 2.7 Sun WorkShop 6 update 1 C
2828 release was reported to work without problems. It worked OK on
2829 another system with Solaris 8 using apparently the same 5.0 compiler
2830 and the default CFLAGS.
2832 **** Solaris 2.x: Emacs dumps core when built with Motif.
2834 The Solaris Motif libraries are buggy, at least up through Solaris 2.5.1.
2835 Install the current Motif runtime library patch appropriate for your host.
2836 (Make sure the patch is current; some older patch versions still have the bug.)
2837 You should install the other patches recommended by Sun for your host, too.
2838 You can obtain Sun patches from ftp://sunsolve.sun.com/pub/patches/;
2839 look for files with names ending in `.PatchReport' to see which patches
2840 are currently recommended for your host.
2842 On Solaris 2.6, Emacs is said to work with Motif when Solaris patch
2843 105284-12 is installed, but fail when 105284-15 is installed.
2844 105284-18 might fix it again.
2846 **** Solaris 2.6 and 7: the Compose key does not work.
2848 This is a bug in Motif in Solaris. Supposedly it has been fixed for
2849 the next major release of Solaris. However, if someone with Sun
2850 support complains to Sun about the bug, they may release a patch.
2851 If you do this, mention Sun bug #4188711.
2853 One workaround is to use a locale that allows non-ASCII characters.
2854 For example, before invoking emacs, set the LC_ALL environment
2855 variable to "en_US" (American English). The directory /usr/lib/locale
2856 lists the supported locales; any locale other than "C" or "POSIX"
2859 pen@lysator.liu.se says (Feb 1998) that the Compose key does work
2860 if you link with the MIT X11 libraries instead of the Solaris X11
2863 *** HP/UX versions before 11.0
2865 HP/UX 10 was end-of-lifed in May 1999.
2867 *** HP/UX 10: Large file support is disabled.
2869 See the comments in src/s/hpux10-20.h.
2871 *** HP/UX: Emacs is slow using X11R5.
2873 This happens if you use the MIT versions of the X libraries--it
2874 doesn't run as fast as HP's version. People sometimes use the version
2875 because they see the HP version doesn't have the libraries libXaw.a,
2876 libXmu.a, libXext.a and others. HP/UX normally doesn't come with
2877 those libraries installed. To get good performance, you need to
2878 install them and rebuild Emacs.
2880 *** Digital Unix 4.0: Garbled display on non-X terminals when Emacs runs.
2882 So far it appears that running `tset' triggers this problem (when TERM
2883 is vt100, at least). If you do not run `tset', then Emacs displays
2884 properly. If someone can tell us precisely which effect of running
2885 `tset' actually causes the problem, we may be able to implement a fix
2890 **** SVr4: On some variants of SVR4, Emacs does not work at all with X.
2892 Try defining BROKEN_FIONREAD in your config.h file. If this solves
2893 the problem, please send a bug report to tell us this is needed; be
2894 sure to say exactly what type of machine and system you are using.
2896 **** SVr4: After running emacs once, subsequent invocations crash.
2898 Some versions of SVR4 have a serious bug in the implementation of the
2899 mmap () system call in the kernel; this causes emacs to run correctly
2900 the first time, and then crash when run a second time.
2902 Contact your vendor and ask for the mmap bug fix; in the mean time,
2903 you may be able to work around the problem by adding a line to your
2904 operating system description file (whose name is reported by the
2905 configure script) that reads:
2906 #define SYSTEM_MALLOC
2907 This makes Emacs use memory less efficiently, but seems to work around
2910 *** SCO Unix and UnixWare
2912 **** SCO 4.2.0: Regular expressions matching bugs on SCO systems.
2914 On SCO, there are problems in regexp matching when Emacs is compiled
2915 with the system compiler. The compiler version is "Microsoft C
2916 version 6", SCO 4.2.0h Dev Sys Maintenance Supplement 01/06/93; Quick
2917 C Compiler Version 1.00.46 (Beta). The solution is to compile with
2920 **** UnixWare 2.1: Error 12 (virtual memory exceeded) when dumping Emacs.
2922 Paul Abrahams (abrahams@acm.org) reports that with the installed
2923 virtual memory settings for UnixWare 2.1.2, an Error 12 occurs during
2924 the "make" that builds Emacs, when running temacs to dump emacs. That
2925 error indicates that the per-process virtual memory limit has been
2926 exceeded. The default limit is probably 32MB. Raising the virtual
2927 memory limit to 40MB should make it possible to finish building Emacs.
2929 You can do this with the command `ulimit' (sh) or `limit' (csh).
2930 But you have to be root to do it.
2932 According to Martin Sohnius, you can also retune this in the kernel:
2934 # /etc/conf/bin/idtune SDATLIM 33554432 ## soft data size limit
2935 # /etc/conf/bin/idtune HDATLIM 33554432 ## hard "
2936 # /etc/conf/bin/idtune SVMMSIZE unlimited ## soft process size limit
2937 # /etc/conf/bin/idtune HVMMSIZE unlimited ## hard "
2938 # /etc/conf/bin/idbuild -B
2940 (He recommends you not change the stack limit, though.)
2941 These changes take effect when you reboot.
2943 ** Windows 3.1, 95, 98, and ME
2945 *** MS-Windows NT/95: Problems running Perl under Emacs
2947 `perl -de 0' just hangs when executed in an Emacs subshell.
2948 The fault lies with Perl (indirectly with Windows NT/95).
2950 The problem is that the Perl debugger explicitly opens a connection to
2951 "CON", which is the DOS/NT equivalent of "/dev/tty", for interacting
2954 On Unix, this is okay, because Emacs (or the shell?) creates a
2955 pseudo-tty so that /dev/tty is really the pipe Emacs is using to
2956 communicate with the subprocess.
2958 On NT, this fails because CON always refers to the handle for the
2959 relevant console (approximately equivalent to a tty), and cannot be
2960 redirected to refer to the pipe Emacs assigned to the subprocess as
2963 A workaround is to modify perldb.pl to use STDIN/STDOUT instead of CON.
2967 *** PERL/LIB/PERLDB.PL.orig Wed May 26 08:24:18 1993
2968 --- PERL/LIB/PERLDB.PL Mon Jul 01 15:28:16 1996
2975 $rcfile="perldb.ini";
2983 $rcfile="perldb.ini";
2988 *** perl/5.001/lib/perl5db.pl.orig Sun Jun 04 21:13:40 1995
2989 --- perl/5.001/lib/perl5db.pl Mon Jul 01 17:00:08 1996
2996 $rcfile="perldb.ini";
3004 $rcfile="perldb.ini";
3008 *** MS-Windows 95: Alt-f6 does not get through to Emacs.
3010 This character seems to be trapped by the kernel in Windows 95.
3011 You can enter M-f6 by typing ESC f6.
3013 *** MS-Windows 95/98/ME: subprocesses do not terminate properly.
3015 This is a limitation of the Operating System, and can cause problems
3016 when shutting down Windows. Ensure that all subprocesses are exited
3017 cleanly before exiting Emacs. For more details, see the FAQ at
3018 http://www.gnu.org/software/emacs/windows/.
3020 *** MS-Windows 95/98/ME: crashes when Emacs invokes non-existent programs.
3022 When a program you are trying to run is not found on the PATH,
3023 Windows might respond by crashing or locking up your system. In
3024 particular, this has been reported when trying to compile a Java
3025 program in JDEE when javac.exe is installed, but not on the system
3030 *** When compiling with DJGPP on MS-Windows NT or later, "config msdos" fails.
3032 If the error message is "VDM has been already loaded", this is because
3033 Windows has a program called `redir.exe' that is incompatible with a
3034 program by the same name supplied with DJGPP, which is used by
3035 config.bat. To resolve this, move the DJGPP's `bin' subdirectory to
3036 the front of your PATH environment variable.
3038 *** When Emacs compiled with DJGPP runs on Windows 2000 and later, it cannot
3039 find your HOME directory.
3041 This was reported to happen when you click on "Save for future
3042 sessions" button in a Customize buffer. You might see an error
3043 message like this one:
3045 basic-save-buffer-2: c:/FOO/BAR/~dosuser/: no such directory
3047 (The telltale sign is the "~USER" part at the end of the directory
3048 Emacs complains about, where USER is your username or the literal
3049 string "dosuser", which is the default username set up by the DJGPP
3050 startup file DJGPP.ENV.)
3052 This happens when the functions `user-login-name' and
3053 `user-real-login-name' return different strings for your username as
3054 Emacs sees it. To correct this, make sure both USER and USERNAME
3055 environment variables are set to the same value. Windows 2000 and
3056 later sets USERNAME, so if you want to keep that, make sure USER is
3057 set to the same value. If you don't want to set USER globally, you
3058 can do it in the [emacs] section of your DJGPP.ENV file.
3060 *** When Emacs compiled with DJGPP runs on Vista, it runs out of memory.
3062 If Emacs running on Vista displays "!MEM FULL!" in the mode line, you
3063 are hitting the memory allocation bugs in the Vista DPMI server. See
3064 msdos/INSTALL for how to work around these bugs (search for "Vista").
3066 *** When compiling with DJGPP on MS-Windows 95, Make fails for some targets
3069 This can happen if long file name support (the setting of environment
3070 variable LFN) when Emacs distribution was unpacked and during
3071 compilation are not the same. See msdos/INSTALL for the explanation
3072 of how to avoid this problem.
3074 *** Emacs compiled with DJGPP complains at startup:
3076 "Wrong type of argument: internal-facep, msdos-menu-active-face"
3078 This can happen if you define an environment variable `TERM'. Emacs
3079 on MSDOS uses an internal terminal emulator which is disabled if the
3080 value of `TERM' is anything but the string "internal". Emacs then
3081 works as if its terminal were a dumb glass teletype that doesn't
3082 support faces. To work around this, arrange for `TERM' to be
3083 undefined when Emacs runs. The best way to do that is to add an
3084 [emacs] section to the DJGPP.ENV file which defines an empty value for
3085 `TERM'; this way, only Emacs gets the empty value, while the rest of
3086 your system works as before.
3088 *** MS-DOS: Emacs crashes at startup.
3090 Some users report that Emacs 19.29 requires dpmi memory management,
3091 and crashes on startup if the system does not have it. We don't yet
3092 know why this happens--perhaps these machines don't have enough real
3093 memory, or perhaps something is wrong in Emacs or the compiler.
3094 However, arranging to use dpmi support is a workaround.
3096 You can find out if you have a dpmi host by running go32 without
3097 arguments; it will tell you if it uses dpmi memory. For more
3098 information about dpmi memory, consult the djgpp FAQ. (djgpp
3099 is the GNU C compiler as packaged for MSDOS.)
3101 Compiling Emacs under MSDOS is extremely sensitive for proper memory
3102 configuration. If you experience problems during compilation, consider
3103 removing some or all memory resident programs (notably disk caches)
3104 and make sure that your memory managers are properly configured. See
3105 the djgpp faq for configuration hints.
3107 *** Emacs compiled with DJGPP for MS-DOS/MS-Windows cannot access files
3108 in the directory with the special name `dev' under the root of any
3109 drive, e.g. `c:/dev'.
3111 This is an unfortunate side-effect of the support for Unix-style
3112 device names such as /dev/null in the DJGPP runtime library. A
3113 work-around is to rename the problem directory to another name.
3115 *** MS-DOS+DJGPP: Problems on MS-DOG if DJGPP v2.0 is used to compile Emacs.
3117 There are two DJGPP library bugs which cause problems:
3119 * Running `shell-command' (or `compile', or `grep') you get
3120 `Searching for program: permission denied (EACCES), c:/command.com';
3121 * After you shell to DOS, Ctrl-Break kills Emacs.
3123 To work around these bugs, you can use two files in the msdos
3124 subdirectory: `is_exec.c' and `sigaction.c'. Compile them and link
3125 them into the Emacs executable `temacs'; then they will replace the
3126 incorrect library functions.
3128 *** MS-DOS: Emacs compiled for MSDOS cannot find some Lisp files, or other
3129 run-time support files, when long filename support is enabled.
3131 Usually, this problem will manifest itself when Emacs exits
3132 immediately after flashing the startup screen, because it cannot find
3133 the Lisp files it needs to load at startup. Redirect Emacs stdout
3134 and stderr to a file to see the error message printed by Emacs.
3136 Another manifestation of this problem is that Emacs is unable to load
3137 the support for editing program sources in languages such as C and
3140 This can happen if the Emacs distribution was unzipped without LFN
3141 support, thus causing long filenames to be truncated to the first 6
3142 characters and a numeric tail that Windows 95 normally attaches to it.
3143 You should unzip the files again with a utility that supports long
3144 filenames (such as djtar from DJGPP or InfoZip's UnZip program
3145 compiled with DJGPP v2). The file msdos/INSTALL explains this issue
3148 Another possible reason for such failures is that Emacs compiled for
3149 MSDOS is used on Windows NT, where long file names are not supported
3150 by this version of Emacs, but the distribution was unpacked by an
3151 unzip program that preserved the long file names instead of truncating
3152 them to DOS 8+3 limits. To be useful on NT, the MSDOS port of Emacs
3153 must be unzipped by a DOS utility, so that long file names are
3156 ** Archaic window managers and toolkits
3158 *** OpenLook: Under OpenLook, the Emacs window disappears when you type M-q.
3160 Some versions of the Open Look window manager interpret M-q as a quit
3161 command for whatever window you are typing at. If you want to use
3162 Emacs with that window manager, you should try to configure the window
3163 manager to use some other command. You can disable the
3164 shortcut keys entirely by adding this line to ~/.OWdefaults:
3166 OpenWindows.WindowMenuAccelerators: False
3168 **** twm: A position you specified in .Xdefaults is ignored, using twm.
3170 twm normally ignores "program-specified" positions.
3171 You can tell it to obey them with this command in your `.twmrc' file:
3173 UsePPosition "on" #allow clients to request a position
3175 ** Bugs related to old DEC hardware
3177 *** The Compose key on a DEC keyboard does not work as Meta key.
3179 This shell command should fix it:
3181 xmodmap -e 'keycode 0xb1 = Meta_L'
3183 *** Keyboard input gets confused after a beep when using a DECserver
3186 This problem seems to be a matter of configuring the DECserver to use
3187 7 bit characters rather than 8 bit characters.
3189 * Build problems on legacy systems
3191 ** BSD/386 1.0: --with-x-toolkit option configures wrong.
3193 This problem is due to bugs in the shell in version 1.0 of BSD/386.
3194 The workaround is to edit the configure file to use some other shell,
3197 ** Digital Unix 4.0: Emacs fails to build, giving error message
3198 Invalid dimension for the charset-ID 160
3200 This is due to a bug or an installation problem in GCC 2.8.0.
3201 Installing a more recent version of GCC fixes the problem.
3203 ** Digital Unix 4.0: Failure in unexec while dumping emacs.
3205 This problem manifests itself as an error message
3207 unexec: Bad address, writing data section to ...
3209 The user suspects that this happened because his X libraries
3210 were built for an older system version,
3212 ./configure --x-includes=/usr/include --x-libraries=/usr/shlib
3214 made the problem go away.
3216 ** SunOS: Emacs gets error message from linker on Sun.
3218 If the error message says that a symbol such as `f68881_used' or
3219 `ffpa_used' or `start_float' is undefined, this probably indicates
3220 that you have compiled some libraries, such as the X libraries,
3221 with a floating point option other than the default.
3223 It's not terribly hard to make this work with small changes in
3224 crt0.c together with linking with Fcrt1.o, Wcrt1.o or Mcrt1.o.
3225 However, the easiest approach is to build Xlib with the default
3226 floating point option: -fsoft.
3228 ** HPUX 10.20: Emacs crashes during dumping on the HPPA machine.
3230 This seems to be due to a GCC bug; it is fixed in GCC 2.8.1.
3232 ** Vax C compiler bugs affecting Emacs.
3234 You may get one of these problems compiling Emacs:
3236 foo.c line nnn: compiler error: no table entry for op STASG
3237 foo.c: fatal error in /lib/ccom
3239 These are due to bugs in the C compiler; the code is valid C.
3240 Unfortunately, the bugs are unpredictable: the same construct
3241 may compile properly or trigger one of these bugs, depending
3242 on what else is in the source file being compiled. Even changes
3243 in header files that should not affect the file being compiled
3244 can affect whether the bug happens. In addition, sometimes files
3245 that compile correctly on one machine get this bug on another machine.
3247 As a result, it is hard for me to make sure this bug will not affect
3248 you. I have attempted to find and alter these constructs, but more
3249 can always appear. However, I can tell you how to deal with it if it
3250 should happen. The bug comes from having an indexed reference to an
3251 array of Lisp_Objects, as an argument in a function call:
3254 ... foo (5, args[i], ...)...
3255 putting the argument into a temporary variable first, as in
3260 ... foo (r, tem, ...)...
3261 causes the problem to go away.
3262 The `contents' field of a Lisp vector is an array of Lisp_Objects,
3263 so you may see the problem happening with indexed references to that.
3265 ** 68000 C compiler problems
3267 Various 68000 compilers have different problems.
3268 These are some that have been observed.
3270 *** Using value of assignment expression on union type loses.
3271 This means that x = y = z; or foo (x = z); does not work
3272 if x is of type Lisp_Object.
3274 *** "cannot reclaim" error.
3276 This means that an expression is too complicated. You get the correct
3277 line number in the error message. The code must be rewritten with
3278 simpler expressions.
3280 *** XCONS, XSTRING, etc macros produce incorrect code.
3282 If temacs fails to run at all, this may be the cause.
3283 Compile this test program and look at the assembler code:
3285 struct foo { char x; unsigned int y : 24; };
3290 test ((int *) arg.y);
3293 If the code is incorrect, your compiler has this problem.
3294 In the XCONS, etc., macros in lisp.h you must replace (a).u.val with
3295 ((a).u.val + coercedummy) where coercedummy is declared as int.
3297 This problem will only happen if USE_LISP_UNION_TYPE is manually
3300 *** C compilers lose on returning unions.
3302 I hear that some C compilers cannot handle returning a union type.
3303 Most of the functions in GNU Emacs return type Lisp_Object, which is
3304 defined as a union on some rare architectures.
3306 This problem will only happen if USE_LISP_UNION_TYPE is manually
3310 This file is part of GNU Emacs.
3312 GNU Emacs is free software: you can redistribute it and/or modify
3313 it under the terms of the GNU General Public License as published by
3314 the Free Software Foundation, either version 3 of the License, or
3315 (at your option) any later version.
3317 GNU Emacs is distributed in the hope that it will be useful,
3318 but WITHOUT ANY WARRANTY; without even the implied warranty of
3319 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
3320 GNU General Public License for more details.
3322 You should have received a copy of the GNU General Public License
3323 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
3328 paragraph-separate: "[
\f]*$"
3331 arch-tag: 49fc0d95-88cb-4715-b21c-f27fb5a4764a