The field that stores mount options in 'struct mnttab' is mnt_mntopts on
OmniOS and mnt_opts on Linux; adjust.

diff -wpruN --no-dereference '--exclude=*.orig' a~/gio/gunixmounts.c a/gio/gunixmounts.c
--- a~/gio/gunixmounts.c	1970-01-01 00:00:00
+++ a/gio/gunixmounts.c	1970-01-01 00:00:00
@@ -712,7 +712,7 @@ _g_unix_mounts_get_from_file (const char
                                              mntent->mnt_dir,
                                              NULL,
                                              mntent->mnt_type,
-                                             mntent->mnt_opts,
+                                             mntent->mnt_mntopts,
                                              is_read_only);
 
       g_hash_table_insert (mounts_hash,
@@ -843,7 +843,7 @@ _g_unix_mounts_get_from_file (const char
                                              mntent.mnt_mountp,
                                              NULL,
                                              mntent.mnt_fstype,
-                                             mntent.mnt_opts,
+                                             mntent.mnt_mntopts,
                                              is_read_only);
 
       g_ptr_array_add (return_array, g_steal_pointer (&mount_entry));
@@ -1363,7 +1363,7 @@ _g_unix_mount_points_get_from_file (cons
       mount_point = create_unix_mount_point (device_path,
                                              mntent->mnt_dir,
                                              mntent->mnt_type,
-                                             mntent->mnt_opts,
+                                             mntent->mnt_mntopts,
                                              is_read_only,
                                              is_user_mountable,
                                              is_loopback);