Otherwise we might be too fast, resulting in failed namespace check
later:
[ 7.351453] testsuite-44.sh[401]: + journalctl --list-namespaces
[ 7.351784] testsuite-44.sh[402]: + grep foobar
[ 7.358851] testsuite-44.sh[402]: foobar
[ 7.359598] testsuite-44.sh[403]: + journalctl --list-namespaces
[ 7.359974] testsuite-44.sh[404]: + grep foobaz
[ 7.369882] systemd[1]: testsuite-44.service: Failed with result 'exit-code'.
Follow-up for
68f66a1713.
systemd-run --wait -p LogNamespace=foobaz echo "hello world"
journalctl --namespace=foobar --sync
+journalctl --namespace=foobaz --sync
+ls -l /var/log/journal/
+journalctl --list-namespaces
+
journalctl -o cat --namespace=foobar >/tmp/hello-world
journalctl -o cat >/tmp/no-hello-world