X-Git-Url: https://git.hcoop.net/jackhill/guix/guix.git/blobdiff_plain/e0b2737583fb06520c65b6a85917f4744db28970..8b030edf021039e87cf27af4ff350dd505957768:/HACKING diff --git a/HACKING b/HACKING dissimilarity index 96% index 44adf5c6d7..aaa673fc93 100644 --- a/HACKING +++ b/HACKING @@ -1,219 +1,20 @@ --*- mode: org; coding: utf-8; -*- - -#+TITLE: Hacking GNU Guix and Its Incredible Distro - -Copyright © 2012, 2013 Ludovic Courtès - - Copying and distribution of this file, with or without modification, - are permitted in any medium without royalty provided the copyright - notice and this notice are preserved. - - -* Running Guix before it is installed - -Command-line tools can be used even if you have not run "make install". -To do that, prefix each command with ‘./pre-inst-env’, as in: - - ./pre-inst-env guix build --help - -Similarly, for a Guile session using the Guix modules: - - ./pre-inst-env guile -c '(use-modules (guix utils)) (pk (%current-system))' - -The ‘pre-inst-env’ script sets up all the environment variables -necessary to support this. - -* The Perfect Setup - -The Perfect Setup to hack on Guix is basically the perfect setup used -for Guile hacking (info "(guile) Using Guile in Emacs"). First, you -need more than an editor, you need [[http://www.gnu.org/software/emacs][Emacs]], empowered by the wonderful -[[http://nongnu.org/geiser/][Geiser]]. - -Geiser allows for interactive and incremental development from within -Emacs: code compilation and evaluation from within buffers, access to -on-line documentation (docstrings), context-sensitive completion, M-. to -jump to an object definition, a REPL to try out your code, and more. - -To actually edit the code, Emacs already has a neat Scheme mode. But in -addition to that, you must not miss [[http://www.emacswiki.org/emacs/ParEdit][Paredit]]. It provides facilities to -directly operate on the syntax tree, such as raising an s-expression or -wrapping it, swallowing or rejecting the following s-expression, etc. - -* Packaging Guidelines - -The GNU distribution is about respecting the freedom of users. Consequently, -it contains only free software as defined at -http://www.gnu.org/philosophy/free-sw.html . - -In addition, we follow the [[http://www.gnu.org/distros/free-system-distribution-guidelines.html][free software distribution guidelines]]. Among other -things, this means that the distribution tries hard not to steer users towards -obtaining information about non-free software. - -* Adding new packages - -Package recipes in Guix look like this: - -#+BEGIN_SRC scheme - (package - (name "nettle") - (version "2.5") - (source - (origin - (method url-fetch) - (uri (string-append "mirror://gnu/nettle/nettle-" - version ".tar.gz")) - (sha256 - (base32 - "0wicr7amx01l03rm0pzgr1qvw3f9blaw17vjsy1301dh13ll58aa")))) - (build-system gnu-build-system) - (inputs `(("m4" ,m4))) - (propagated-inputs `(("gmp" ,gmp))) - (home-page - "http://www.lysator.liu.se/~nisse/nettle/") - (synopsis "GNU Nettle, a cryptographic library") - (description - "Nettle is a cryptographic library...") - (license gpl2+)) -#+END_SRC - -Such a recipe can be written by hand, and then tested by running -‘./pre-inst-env guix build nettle’. - -When writing the recipe, the base32-encoded SHA256 hash of the source -code tarball, which can be seen in the example above, can be obtained by -running: - - guix download http://ftp.gnu.org/gnu/nettle/nettle-2.5.tar.gz - -Alternatively, it is possible to semi-automatically import recipes from -the [[http://nixos.org/nixpkgs/][Nixpkgs]] software distribution using this command: - - guix import /path/to/nixpkgs/checkout nettle - -The command automatically fetches and converts to Guix the “Nix -expression” of Nettle. - -* Submitting Patches - -Development is done using the Git distributed version control system. Thus, -access to the repository is not strictly necessary. We welcome contributions -in the form of patches as produced by ‘git format-patch’ sent to -bug-guix@gnu.org. Please write commit logs in the [[http://www.gnu.org/prep/standards/html_node/Change-Logs.html#Change-Logs][GNU ChangeLog format]]. - -As you become a regular contributor, you may find it convenient to have write -access to the repository (see below.) - -* Commit Access - -For frequent contributors, having write access to the repository is -convenient. When you deem it necessary, feel free to ask for it on the -mailing list. When you get commit access, please make sure to follow the -policy below (discussions of the policy can take place on bug-guix@gnu.org.) - -Non-trivial patches should always be posted to bug-guix@gnu.org (trivial -patches include fixing typos, etc.) - -For patches that just add a new package, and a simple one, it’s OK to commit, -if you’re confident (which means you successfully built it in a chroot setup.) -Likewise for package upgrades. We have a mailing list for commit -notifications (guix-commits@gnu.org), so people can notice. Before pushing -your changes, make sure to run ‘git pull --rebase’. - -For anything else, please post to bug-guix@gnu.org and leave time for a -review, without committing anything. If you didn’t receive any reply -after two weeks, and if you’re confident, it’s OK to commit. - -That last part is subject to being adjusted, allowing individuals to commit -directly on non-controversial changes on parts they’re familiar with. - -* Porting the Guix distro on a new platform - -** Introduction - -Unlike Make or similar build tools, Guix requires absolutely /all/ the -dependencies of a build process to be specified. - -For a user-land software distribution, that means that the process that -builds GCC (then used to build all other programs) must itself be -specified; and the process to build the C library to build that GCC; and -the process to build the GCC to build that library; and... See the -problem? Chicken-and-egg. - -To break that cycle, the distro starts from a set of pre-built -binaries–usually referred to as “bootstrap binaries.” These include -statically-linked versions of Guile, GCC, Coreutils, Grep, sed, -etc., and the GNU C Library. - -This section describes how to build those bootstrap binaries when -porting to a new platform. - -** When the platform is supported by Nixpkgs - -In that case, the easiest thing is to bootstrap the distro using -binaries from Nixpkgs. - -To do that, you need to comment out the definitions of -‘%bootstrap-guile’ and ‘%bootstrap-inputs’ in gnu/packages/bootstrap.scm -to force the use of Nixpkgs derivations. For instance, when porting to -‘i686-linux’, you should redefine these variables along these lines: - -#+BEGIN_SRC scheme - (define %bootstrap-guile - (nixpkgs-derivation "guile" "i686-linux")) - - (define %bootstrap-inputs - (compile-time-value - `(("libc" ,(nixpkgs-derivation "glibc" "i686-linux")) - ,@(map (lambda (name) - (list name (nixpkgs-derivation name "i686-linux"))) - '("gnutar" "gzip" "bzip2" "xz" "patch" - "coreutils" "gnused" "gnugrep" "bash" - "gawk" ; used by `config.status' - "gcc" "binutils"))))) -#+END_SRC - -That should allow the distro to be bootstrapped. - -Then, the tarballs containing the initial binaries of Guile, Coreutils, -GCC, libc, etc. need to be built. To that end, run the following -commands: - -#+BEGIN_SRC sh - ./pre-inst-env guix build -K \ - -e '(@ (gnu packages make-bootstrap) %bootstrap-tarballs)' \ - --system=i686-linux - -#+END_SRC - -These should build tarballs containing statically-linked tools usable on -that system. - -In the source tree, you need to install binaries for ‘mkdir’, ‘bash’, -‘tar’, and ‘xz’ under ‘gnu/packages/bootstrap/i686-linux’. These -binaries can be extracted from the static-binaries tarball built above. - -A rule for ‘gnu/packages/bootstrap/i686-linux/guile-2.0.7.tar.xz’ -needs to be added in ‘Makefile.am’, with the appropriate hexadecimal -vrepresentation of its SHA256 hash. - -You may then revert your changes to ‘bootstrap.scm’. For the variables -‘%bootstrap-coreutils&co’, ‘%bootstrap-binutils’, ‘%bootstrap-glibc’, -and ‘%bootstrap-gcc’, the expected SHA256 of the corresponding tarballs -for ‘i686-linux’ (built above) must be added. - -This should be enough to bootstrap the distro without resorting to -Nixpkgs. - -** When the platform is *not* supported by Nixpkgs - -In that case, the bootstrap binaries should be built using whatever -tools are available on the target platform. That is, the tarballs and -binaries show above must first be built manually, using the available -tools. - -They should have the same properties as those built by the Guix recipes -shown above. For example, all the binaries (except for glibc) must be -statically-linked; the bootstrap Guile must be relocatable (see patch in -the Guix distro); the static-binaries tarball must contain the same -programs (Coreutils, Grep, sed, Awk, etc.); and so on. +-*- mode: org; coding: utf-8; -*- + +#+TITLE: Hacking GNU Guix and Its Incredible Distro + +Copyright © 2012, 2013, 2014, 2016, 2017, 2019 Ludovic Courtès +Copyright © 2015, 2017 Mathieu Lirzin +Copyright © 2017 Leo Famulari +Copyright © 2017 Arun Isaac + + Copying and distribution of this file, with or without modification, + are permitted in any medium without royalty provided the copyright + notice and this notice are preserved. + +* Contributing + +See the manual for useful hacking informations, either by running + + info -f doc/guix.info "Contributing" + +or by checking the [[https://guix.gnu.org/manual/devel/en/html_node/Contributing.html][web copy of the manual]].