timeout cmd

I was investigating performance regression, to do with caching (or missing places that needed caching). I would run pytest and wait for it to complete and see if the execution time was longer than baseline. This ended up being real tedious because it’s hard to tell the difference between 20-25 seconds and 35-40 seconds. Then I discovered timeout.

timeout 30s pytest tests/

The timeout command accepts a time duration, after which it will send a signal to the spawned process. The timeout can be specified in different units (e.g. 1h) and the signal can be changed from the default of SIGTERM. There’s also an option to send SIGKILL after sending the first signal, to forcefully kill the process if needed.