06/06: activation: Check whether /proc/sys/kernel/modprobe exists.

[guix-commits]

civodul pushed a commit to branch master
in repository guix.

commit 83460433b94487198750ad0bcc6f3869f68a8c8f
Author: address@hidden <address@hidden>
AuthorDate: Thu Jan 2 15:13:45 2020 +0300

    activation: Check whether /proc/sys/kernel/modprobe exists.
    
    * gnu/build/activation.scm (activate-modprobe): Check whether
    /proc/sys/kernel/modprobe exists before writing to it.
    
    Co-authored-by: Ludovic Courtès <address@hidden>
---
 gnu/build/activation.scm | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/gnu/build/activation.scm b/gnu/build/activation.scm
index 6d69628..30f5e87 100644
--- a/gnu/build/activation.scm
+++ b/gnu/build/activation.scm
@@ -281,9 +281,13 @@ second element is the name it should appear at, such as:
 
 (define (activate-modprobe modprobe)
   "Tell the kernel to use MODPROBE to load modules."
-  (call-with-output-file "/proc/sys/kernel/modprobe"
-    (lambda (port)
-      (display modprobe port))))
+
+  ;; If the kernel was built without loadable module support, this file is
+  ;; unavailable, so check for its existence first.
+  (when (file-exists? "/proc/sys/kernel/modprobe")
+    (call-with-output-file "/proc/sys/kernel/modprobe"
+      (lambda (port)
+        (display modprobe port)))))
 
 (define (activate-firmware directory)
   "Tell the kernel to look for device firmware under DIRECTORY.  This