print errno if char device creation fails

on Ubuntu autopkgtest runs on armhf, /dev/zero creation fails.

(cherry picked from commit 8db532f305b84b7e7e83133709244d8b502033f3)

1 files changed, 2 insertions, 1 deletions

diff --git a/src/firejail/fs_dev.c b/src/firejail/fs_dev.c
index d807f527d..ce5d1bc96 100644
--- a/src/firejail/fs_dev.c
+++ b/src/firejail/fs_dev.c
@@ -25,6 +25,7 @@
 #include <dirent.h>
 #include <fcntl.h>
 #include <pwd.h>
+#include <errno.h>
 #ifndef _BSD_SOURCE
 #define _BSD_SOURCE
 #endif
@@ -148,7 +149,7 @@ static void create_char_dev(const char *path, mode_t mode, int major, int minor)
         return;
 
 errexit:
-        fprintf(stderr, "Error: cannot create %s device\n", path);
+        fprintf(stderr, "Error: cannot create %s device: %s\n", path, strerror(errno));
         exit(1);
 }