of an element. @xref{Invoking guix graph}, for a tool to visualize
the graph of references.
+@item --derivers
+@cindex derivation
+Return the derivation(s) leading to the given store items
+(@pxref{Derivations}).
+
+For example, this command:
+
+@example
+guix gc --derivers `guix package -I ^emacs$ | cut -f4`
+@end example
+
+@noindent
+returns the @file{.drv} file(s) leading to the @code{emacs} package
+installed in your profile.
+
+Note that there may be zero matching @file{.drv} files, for instance
+because these files have been garbage-collected. There can also be more
+than one matching @file{.drv} due to fixed-output derivations.
@end table
Lastly, the following options allow you to check the integrity of the
;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2012, 2013, 2015, 2016, 2017 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2012, 2013, 2015, 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
;;;
;;; This file is part of GNU Guix.
;;;
-R, --requisites list the requisites of PATHS"))
(display (G_ "
--referrers list the referrers of PATHS"))
+ (display (G_ "
+ --derivers list the derivers of PATHS"))
(newline)
(display (G_ "
--verify[=OPTS] verify the integrity of the store; OPTS is a
(lambda (opt name arg result)
(alist-cons 'action 'list-referrers
(alist-delete 'action result))))
+ (option '("derivers") #f #f
+ (lambda (opt name arg result)
+ (alist-cons 'action 'list-derivers
+ (alist-delete 'action result))))
(option '("list-failures") #f #f
(lambda (opt name arg result)
(alist-cons 'action 'list-failures
(requisites store (list item)))))
((list-referrers)
(list-relatives referrers))
+ ((list-derivers)
+ (list-relatives valid-derivers))
((optimize)
(assert-no-extra-arguments)
(optimize-store store))
# GNU Guix --- Functional package management for GNU
-# Copyright © 2013, 2015, 2017 Ludovic Courtès <ludo@gnu.org>
+# Copyright © 2013, 2015, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
#
# This file is part of GNU Guix.
#
if guix gc --references /dev/null;
then false; else true; fi
+# Check derivers.
+guix gc --derivers "$out" | grep "$drv"
+
# Add then reclaim a .drv file.
drv="`guix build idutils -d`"
test -f "$drv"