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| | ;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2021 Maxim Cournoyer <maxim.cournoyer@gmail.com>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (guix build pack)
#:use-module (guix build utils)
#:export (tar-base-options))
(define* (tar-base-options #:key tar compressor)
"Return the base GNU tar options required to produce deterministic archives
deterministically. When TAR, a GNU tar command file name, is provided, the
`--sort' option is used only if supported. When COMPRESSOR, a command such as
'(\"gzip\" \"-9n\"), is provided, the compressor is explicitly specified via
the `-I' option."
(define (tar-supports-sort? tar)
(zero? (system* tar "cf" "/dev/null" "--files-from=/dev/null"
"--sort=name")))
`(,@(if compressor
(list "-I" (string-join compressor))
'())
;; The --sort option was added to GNU tar in version 1.28, released
;; 2014-07-28. For testing, we use the bootstrap tar, which is older
;; and doesn't support it.
,@(if (and=> tar tar-supports-sort?)
'("--sort=name")
'())
;; Use GNU format so there's no file name length limitation.
"--format=gnu"
"--mtime=@1"
"--owner=root:0"
"--group=root:0"
;; The 'nlink' of the store item files leads tar to store hard links
;; instead of actual copies. However, the 'nlink' count depends on
;; deduplication in the store; it's an "implicit input" to the build
;; process. Use '--hard-dereference' to eliminate it.
"--hard-dereference"
"--check-links"))
|