systemctl: show error when help for unknown unit is requested

Fixes #20189. We would only log at debug level and return failure, which looks
like a noop for the user.

('help' accepts multiple arguments and will show multiple concatenated man
pages in that case. Actually, it will also show multiple concatenated man pages
if the Documentation= setting lists multiple pages. I don't think it's very
terribly useful, but, meh, I don't think we can do much better. If a user
requests a help for a two services, one known and one unknown, there'll now be
a line in the output. It's not very user friendly, but not exactly wrong too.)

(cherry picked from commit 75312ada5324d8adae3f3a0ed97f0acfc8b8bde5)
(cherry picked from commit 486412ad3bba4f1306597302cf66cc4858126243)
(cherry picked from commit ee0cf3ef6f522ee084ed987593f55c6c32097619)

diff --git a/src/systemctl/systemctl-show.c b/src/systemctl/systemctl-show.c
index 7feb2de22eae6fcaf079b1764265fa4658853dfd..de256b649f7739aeec6a706ff5421ef1df781980 100644 (file)
--- a/src/systemctl/systemctl-show.c
+++ b/src/systemctl/systemctl-show.c
@@ -1858,7 +1858,7 @@ static int show_one(
                 return log_error_errno(r, "Failed to get properties: %s", bus_error_message(&error, r));
 
         if (unit && streq_ptr(info.load_state, "not-found") && streq_ptr(info.active_state, "inactive")) {
-                log_full(show_mode == SYSTEMCTL_SHOW_STATUS ? LOG_ERR : LOG_DEBUG,
+                log_full(show_mode == SYSTEMCTL_SHOW_PROPERTIES ? LOG_DEBUG : LOG_ERR,
                          "Unit %s could not be found.", unit);
 
                 if (show_mode == SYSTEMCTL_SHOW_STATUS)