shell-completion: fix completion of `systemctl --user unset-environment` (#37409)

Co-authored-by: Eisuke Kawashima <e-kwsm@users.noreply.github.com>
(cherry picked from commit 6d07d23b022d48898d9a2e7181ab6493d3d61c43)
(cherry picked from commit 11c16d414ebbcb13e39971d90ece4a1e0db183d2)

diff --git a/shell-completion/zsh/_systemctl.in b/shell-completion/zsh/_systemctl.in
index df9045f229bca71f9120a89df5ed7a2cfe6a7910..c787c42af7f8ec81c55beb4e8dd457095d81c212 100644 (file)
--- a/shell-completion/zsh/_systemctl.in
+++ b/shell-completion/zsh/_systemctl.in
@@ -412,7 +412,7 @@ for fun in set-environment unset-environment ; do
             suf='-S='
         fi
         _wanted systemd-environment expl 'environment variable' \
-                compadd "$@" ${suf} - ${${(f)"$(systemctl show-environment)"}%%=*}
+                compadd "$@" ${suf} - ${${(f)"$(systemctl "$_sys_service_mgr" show-environment)"}%%=*}
     }
 done