04/07: services: nscd: Adjust activation snippet for /etc/resolv.conf symlinks.

[Ludovic Courtès]

civodul pushed a commit to branch master
in repository guix.

commit c298fb133acbdc17e05a79c10ab9a9e214368264
Author: Ludovic Courtès <address@hidden>
Date:   Mon May 8 15:07:52 2017 +0200

    services: nscd: Adjust activation snippet for /etc/resolv.conf symlinks.
    
    Fixes <http://bugs.gnu.org/26809>.
    Reported by Mark H Weaver <address@hidden>.
    
    * gnu/services/base.scm (nscd-activation): Use 'lstat' instead of
    'file-exists?'.
---
 gnu/services/base.scm | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/gnu/services/base.scm b/gnu/services/base.scm
index a64faa0..c244174 100644
--- a/gnu/services/base.scm
+++ b/gnu/services/base.scm
@@ -1152,8 +1152,10 @@ the tty to run, among other things."
       (mkdir-p "/var/db/nscd")                    ;for the persistent cache
 
       ;; In libc 2.25 nscd uses inotify to watch /etc/resolv.conf, but only if
-      ;; that file exists when it is started.  Thus create it here.
-      (unless (file-exists? "/etc/resolv.conf")
+      ;; that file exists when it is started.  Thus create it here.  Note: on
+      ;; some systems, such as when NetworkManager is used, /etc/resolv.conf
+      ;; is a symlink, hence 'lstat'.
+      (unless (false-if-exception (lstat "/etc/resolv.conf"))
         (call-with-output-file "/etc/resolv.conf"
           (lambda (port)
             (display "# This is a placeholder.\n" port))))))