nspawn: do not emit any warning when $UNIFIED_CGROUP_HIERARCHY is used

Initially I thought this is a good idea, but when reviewing a different PR
(https://github.com/systemd/systemd/pull/13862#discussion_r340604313) I changed
my mind about this. At some point we probably should start warning about the
old option name, and yet later remove it. But it'll make it easier for people
to transition to the new option name if there's a period of support for both
names without any fuss. There's nothing particularly wrong about the old name,
and there is no support cost.

Fixes #13919 (by avoiding the issue completely).

1 files changed, 1 insertions, 6 deletions

diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index c87e859194..ea781e2b38 100644
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -437,14 +437,9 @@ static int detect_unified_cgroup_hierarchy_from_environment(void) {
 
         e = getenv(var);
         if (!e) {
-                static bool warned = false;
-
+                /* $UNIFIED_CGROUP_HIERARCHY has been renamed to $SYSTEMD_NSPAWN_UNIFIED_HIERARCHY. */
                 var = "UNIFIED_CGROUP_HIERARCHY";
                 e = getenv(var);
-                if (e && !warned) {
-                        log_info("$UNIFIED_CGROUP_HIERARCHY has been renamed to $SYSTEMD_NSPAWN_UNIFIED_HIERARCHY.");
-                        warned = true;
-                }
         }
 
         if (!isempty(e)) {