[bug#59253] [PATCH] gnu: emacs-magit: Substitute git executable path.

[Thiago Jung Bauermann]

Magit has a strong dependency on Git so it should directly reference the
git executable rather than expect it to be available in the profile or
environment.

This also fixes a build failure in emacs-forge.

* gnu/packages/emacs-xyz.scm (emacs-magit)[arguments]<#:phases>: Substitute
git path in the ‘magit-git-executable’ variable.
---
 gnu/packages/emacs-xyz.scm | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/gnu/packages/emacs-xyz.scm b/gnu/packages/emacs-xyz.scm
index 8ff6275bad96..1406f8a715f2 100644
--- a/gnu/packages/emacs-xyz.scm
+++ b/gnu/packages/emacs-xyz.scm
@@ -117,6 +117,7 @@
 ;;; Copyright © 2022 Jose G Perez Taveras <josegpt27@gmail.com>
 ;;; Copyright © 2022 Hilton Chain <hako@ultrarare.space>
 ;;; Copyright © 2022 Nicolas Graves <ngraves@ngraves.fr>
+;;; Copyright © 2022 Thiago Jung Bauermann <bauermann@kolabnow.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -1031,7 +1032,11 @@ (define-public emacs-magit
                   ("magit-version" #$version))))
             (add-after 'set-magit-version 'patch-exec-paths
               (lambda* (#:key inputs #:allow-other-keys)
-                (make-file-writable "lisp/magit-sequence.el")
+                (for-each make-file-writable
+                          (list "lisp/magit-git.el" "lisp/magit-sequence.el"))
+                (emacs-substitute-variables "lisp/magit-git.el"
+                  ("magit-git-executable"
+                   (search-input-file inputs "/bin/git")))
                 (emacs-substitute-variables "lisp/magit-sequence.el"
                   ("magit-perl-executable"
                    (search-input-file inputs "/bin/perl")))))