This is the development repository for the Timewarrior on-modify hook script for Taskwarrior.
The hook script is released as on-modify.timewarrior with Timewarrior.
You can find it here in the current release.
Copy the script to the ~/.task/hooks directory.
Create that directory if necessary, and make sure the script is executable.
If you want to try this version of the hook script, copy it as on-modify.timewarrior to the ~/.task/hooks directory.