linux-initrd: Skip initrd module check when 'modules.alias' can't be found.

Fixes <https://bugs.gnu.org/30760>.
Reported by Tomáš Čech <sleep_walker@gnu.org>.

* gnu/system/linux-initrd.scm (check-device-initrd-modules): Call
'known-module-aliases' and catch 'system-error around it.  Pass it to
'matching-modules'.

gnu/system/linux-initrd.scm

@@ -353,17 +353,27 @@ loaded at boot time in the order in which they appear."
 (define (check-device-initrd-modules device linux-modules location)
   "Raise an error if DEVICE needs modules beyond LINUX-MODULES to operate.
 DEVICE must be a \"/dev\" file name."
-  (let ((modules (delete-duplicates
-                  (append-map matching-modules
-                              (device-module-aliases device)))))
-    (unless (every (cute member <> linux-modules) modules)
-      (raise (condition
-              (&message
-               (message (format #f (G_ "you may need these modules \
+  (define aliases
+    ;; Attempt to load 'modules.alias' from the current kernel, assuming we're
+    ;; on GuixSD, and assuming that corresponds to the kernel we'll be
+    ;; installing.  Skip the whole thing if that file cannot be read.
+    (catch 'system-error
+      (lambda ()
+        (known-module-aliases))
+      (const #f)))
+
+  (when aliases
+    (let ((modules (delete-duplicates
+                    (append-map (cut matching-modules <> aliases)
+                                (device-module-aliases device)))))
+      (unless (every (cute member <> linux-modules) modules)
+        (raise (condition
+                (&message
+                 (message (format #f (G_ "you may need these modules \
 in the initrd for ~a:~{ ~a~}")
-                                device modules)))
-              (&fix-hint
-               (hint (format #f (G_ "Try adding them to the
+                                  device modules)))
+                (&fix-hint
+                 (hint (format #f (G_ "Try adding them to the
 @code{initrd-modules} field of your @code{operating-system} declaration, along
 these lines:
 
@@ -373,8 +383,8 @@ these lines:
    (initrd-modules (append (list~{ ~s~})
                            %base-initrd-modules)))
 @end example\n")
-                             modules)))
-              (&error-location
-               (location (source-properties->location location))))))))
+                               modules)))
+                (&error-location
+                 (location (source-properties->location location)))))))))
 
 ;;; linux-initrd.scm ends here