systemctl: fix silent failure when --root is not found

Some calls to lookup_path_init() were not followed by any log emission.
E.g.:
$ SYSTEMD_LOG_LEVEL=debug systemctl --root=/missing enable unit; echo $?
1

Let's add a helper function and use it in various places.

$ SYSTEMD_LOG_LEVEL=debug build/systemctl --root=/missing enable unit; echo $?
Failed to initialize unit search paths for root directory /missing: No such file or directory
1
$ SYSTEMCTL_SKIP_SYSV=1 build/systemctl --root=/missing enable unit; echo $?
Failed to initialize unit search paths for root directory /missing: No such file or directory
Failed to enable: No such file or directory.
1

The repeated error in the second case is not very nice, but this is a niche
case and I don't think it's worth the trouble to trying to avoid it.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/systemctl/systemctl-sysv-compat.c b/src/systemctl/systemctl-sysv-compat.c
index 017dba2034..c6e8defd1b 100644
--- a/src/systemctl/systemctl-sysv-compat.c
+++ b/src/systemctl/systemctl-sysv-compat.c
@@ -128,7 +128,7 @@ int enable_sysv_units(const char *verb, char **args) {
                         "is-enabled"))
                 return 0;
 
-        r = lookup_paths_init(&paths, arg_scope, LOOKUP_PATHS_EXCLUDE_GENERATED, arg_root);
+        r = lookup_paths_init_or_warn(&paths, arg_scope, LOOKUP_PATHS_EXCLUDE_GENERATED, arg_root);
         if (r < 0)
                 return r;