python3-pywatchman 4.9.0-7build1 (amd64 binary) in ubuntu lunar

 A Python library for watchman (the file watching service), and related
 utilities such as watchman-make and watchman-wait. Watchman can be used
 to watch files and record when they actually change. It can be used
 to trigger actions (such as rebuilding assets) when matching files
 change. If you require to perform an action based on whether a file
 changes or not, watchman may be the tool you need. By giving watchman
 a pattern and an action to take when the files change, you can trigger
 an activity to be taken.