Improve messages about user mode a bit

TODO

@@ -17,6 +17,8 @@ Bugfixes:
 
   Cannot add dependency job for unit display-manager.service, ignoring: Unit display-manager.service failed to load: No such file or directory. See system logs and 'systemctl status display-manager.service' for details.
 
+* systemctl --root=container/ set-default ... is totally borked.
+
 External:
 
 * ps should gain colums for slice

src/core/main.c

@@ -1475,8 +1475,11 @@ int main(int argc, char *argv[]) {
                 if (in_initrd())
                         log_info("Running in initial RAM disk.");
 
-        } else
-                log_debug(PACKAGE_STRING " running in user mode. (" SYSTEMD_FEATURES ")");
+        } else {
+                _cleanup_free_ char *t = uid_to_name(getuid());
+                log_debug(PACKAGE_STRING " running in user mode for user "PID_FMT"/%s. (" SYSTEMD_FEATURES ")",
+                          getuid(), t);
+        }
 
         if (arg_running_as == SYSTEMD_SYSTEM && !skip_setup) {
                 if (arg_show_status || plymouth_running())

units/user@.service.in

@@ -6,7 +6,7 @@
 #  (at your option) any later version.
 
 [Unit]
-Description=User Manager for %i
+Description=User Manager for UID %i
 After=systemd-user-sessions.service
 
 [Service]