[bug#63508] [PATCH v4 2/2] gnu: eudev: Have udevadm look in /etc/udev/rules.d. (Closes: #63508)

[Felix Lechner]

This substitution ensures that udevadm sees the rules that are actually in
effect for the declared operating system. It allows administrators to use the
udev-rules-service for network interfaces.

Some of Guix's customizations for udev rules appear to work as it is [1] but
that is not true for network interfaces (which invoke udevadm for naming
purposes). [2]

Without this commit, udevadm will consult the rules that were present at build
time and were installed in the store).

[1] https://lists.gnu.org/archive/html/guix-devel/2023-05/msg00195.html
[2] https://lists.gnu.org/archive/html/guix-devel/2023-05/msg00192.html

* gnu/packages/linux.scm (eudev): Have udevadm look in
/etc/udev/rules.d. (Closes: #63508)
---
 gnu/packages/linux.scm | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/gnu/packages/linux.scm b/gnu/packages/linux.scm
index 7a365e2e22..55255e576e 100644
--- a/gnu/packages/linux.scm
+++ b/gnu/packages/linux.scm
@@ -4192,6 +4192,11 @@ (define-public eudev
      (list
       #:phases
       #~(modify-phases %standard-phases
+          (add-before 'bootstrap 'hardcode-runtime-rules-dir
+            (lambda _
+              (use-modules (ice-9 regex))
+              (substitute* "src/udev/Makefile.am"
+                (((regexp-quote "$(udevrulesdir)")) "/etc/udev/rules.d"))))
           (add-before 'bootstrap 'patch-file-names
             (lambda* (#:key inputs native-inputs #:allow-other-keys)
               (substitute* "man/make.sh"
-- 
2.40.1