`cmp` lives in diffutils, not coreutils, so the root-changed test exited
127 with "command not found". Inside `if ! cmp -s`, a 127 reads as
"differs" and errexit never sees it, so `rootchanged` was 1 on every run
and the trust-bundle rebuild it guards bounced `hive-tls-ca` after each
issuance — the exact "only a changed one, or every boot would bounce a
unit with nothing to do" the comment there rules out.
Found in the journal of a hive that had just issued a leaf successfully:
the unit logged "the services root changed" on a run where the store had
left the issuer alone.
11ec050ca8