bug#62181: [PATCH v2 1/2] gnu: gnulib: Reset the shebangs.

[Vivien Kraus via Bug reports for GNU Guix <bug-guix@gnu.org>]

* gnu/packages/build-tools.scm (gnulib) [phase reset-shebangs]: After
installation, rewrite the /gnu/store shebangs in the distributed build-aux
files.
[inputs, native-inputs]: Add bash-minimal.
[phase let-autogen-execute-gnulib-tool]: Specify a shell to execute
gnulib-tool from autogen.sh.
---
 gnu/packages/build-tools.scm | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/gnu/packages/build-tools.scm b/gnu/packages/build-tools.scm
index 28ab77bbb4..caf0f3fc1c 100644
--- a/gnu/packages/build-tools.scm
+++ b/gnu/packages/build-tools.scm
@@ -973,12 +973,25 @@ (define (find-ucd-files . names)
                    ("NormalizationTest.txt" . "uninorm")
                    ("auxiliary/GraphemeBreakTest.txt" . "unigbrk")
                    ("auxiliary/WordBreakTest.txt" . "uniwbrk")))
-                (delete-file "gen-uni-tables")))))))
-    (inputs ;; Shebangs for some auxiliary build files.
-     (list python perl clisp))
+                (delete-file "gen-uni-tables"))))
+          (add-after 'install 'restore-shebangs
+            (lambda _
+              (substitute* (find-files
+                            (string-append #$output "/src/gnulib")
+                            (lambda (fname stat)
+                              (and (not (string-suffix? "/lib/javaversion.class" fname))
+                                   (not (string-suffix? ".mo" fname)))))
+                (("^#! ?(.*)/bin/sh" _ prefix)
+                 "#!/bin/sh")
+                (("^#! ?(.*)/bin/python3" _ prefix)
+                 "#!/usr/bin/env python3")
+                (("^#! ?(.*)/bin/([a-zA-Z0-9-]+)" _ prefix program)
+                 (string-append "#!/usr/bin/" program))))))))
+    (inputs ;; Shebang for gnulib-tool
+     (list bash-minimal))
     (native-inputs
      (list
-      python perl clisp
+      bash-minimal python perl clisp
       ;; Unicode data:
       ucd-next
       ;; Programs for the tests:
-- 
2.39.2