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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2014, 2016, 2019, 2023-2024 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2023 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 git)
#:use-module (guix build utils)
#:autoload (guix build download-nar) (download-nar)
#:autoload (guix swh) (%verify-swh-certificate?
swh-download
swh-download-directory-by-nar-hash)
#:use-module (srfi srfi-34)
#:use-module (ice-9 format)
#:export (git-fetch
git-fetch-with-fallback))
;;; Commentary:
;;;
;;; This is the build-side support code of (guix git-download). It allows a
;;; Git repository to be cloned and checked out at a specific commit.
;;;
;;; Code:
(define* (git-fetch url commit directory
#:key (git-command "git")
lfs? recursive?)
"Fetch COMMIT from URL into DIRECTORY. COMMIT must be a valid Git commit
identifier. When LFS? is true, configure Git to also fetch Large File
Storage (LFS) files; it assumes that the @code{git-lfs} extension is available
in the environment. When RECURSIVE? is true, all the sub-modules of URL are
fetched, recursively. Return #t on success, #f otherwise."
;; Disable TLS certificate verification. The hash of the checkout is known
;; in advance anyway.
(setenv "GIT_SSL_NO_VERIFY" "true")
(mkdir-p directory)
(guard (c ((invoke-error? c)
(format (current-error-port)
"git-fetch: '~a~{ ~a~}' failed with exit code ~a~%"
(invoke-error-program c)
(invoke-error-arguments c)
(or (invoke-error-exit-status c) ;XXX: not quite accurate
(invoke-error-stop-signal c)
(invoke-error-term-signal c)))
(delete-file-recursively directory)
#f))
(with-directory-excursion directory
(invoke git-command "init" "--initial-branch=main")
(invoke git-command "remote" "add" "origin" url)
(when lfs?
(setenv "HOME" "/tmp")
(invoke git-command "lfs" "install"))
(if (zero? (system* git-command "fetch" "--depth" "1" "origin" commit))
(invoke git-command "checkout" "FETCH_HEAD")
(begin
(setvbuf (current-output-port) 'line)
(format #t "Failed to do a shallow fetch; retrying a full fetch...~%")
(invoke git-command "fetch" "origin")
(invoke git-command "checkout" commit)))
(when recursive?
;; Now is the time to fetch sub-modules.
(invoke git-command "submodule" "update" "--init" "--recursive")
;; In sub-modules, '.git' is a flat file, not a directory,
;; so we can use 'find-files' here.
(for-each delete-file-recursively
(find-files directory "^\\.git$")))
;; The contents of '.git' vary as a function of the current
;; status of the Git repo. Since we want a fixed output, this
;; directory needs to be taken out.
(delete-file-recursively ".git")
#t)))
(define* (git-fetch-with-fallback url commit directory
#:key (git-command "git")
hash hash-algorithm
lfs? recursive?)
"Like 'git-fetch', fetch COMMIT from URL into DIRECTORY, but fall back to
alternative methods when fetching from URL fails: attempt to download a nar,
and if that also fails, download from the Software Heritage archive. When
HASH and HASH-ALGORITHM are provided, they are interpreted as the nar hash of
the directory of interested and are used as its content address at SWH."
(or (git-fetch url commit directory
#:lfs? lfs?
#:recursive? recursive?
#:git-command git-command)
(download-nar directory)
;; As a last resort, attempt to download from Software Heritage.
;; Disable X.509 certificate verification to avoid depending
;; on nss-certs--we're authenticating the checkout anyway.
;; XXX: Currently recursive checkouts are not supported.
(and (not recursive?)
(parameterize ((%verify-swh-certificate? #f))
(format (current-error-port)
"Trying to download from Software Heritage...~%")
;; First try to look up and download the directory corresponding
;; to HASH: this is fundamentally more reliable than looking up
;; COMMIT, especially when COMMIT denotes a tag.
(or (and hash hash-algorithm
(swh-download-directory-by-nar-hash hash hash-algorithm
directory))
(swh-download url commit directory))
(when (file-exists?
(string-append directory "/.gitattributes"))
;; Perform CR/LF conversion and other changes
;; specificied by '.gitattributes'.
(invoke git-command "-C" directory "init")
(invoke git-command "-C" directory "config" "--local"
"user.email" "you@example.org")
(invoke git-command "-C" directory "config" "--local"
"user.name" "Your Name")
(invoke git-command "-C" directory "add" ".")
(invoke git-command "-C" directory "commit" "-am" "init")
(invoke git-command "-C" directory "read-tree" "--empty")
(invoke git-command "-C" directory "reset" "--hard")
(delete-file-recursively
(string-append directory "/.git")))))))
;;; git.scm ends here
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