Watchdog: argh not found

[bhargavrpatel]

In the latest version of watchdog (0.10.0), we have to currently, explicitly install argh in order our processes to start. Without argh explicitly installed, we see the following exception:

Traceback (most recent call last):
  File "/env/bin/watchmedo", line 6, in <module>
    from watchdog.watchmedo import main
  File "/env/lib/python3.7/site-packages/watchdog/watchmedo.py", line 39, in <module>
    from argh import arg, aliases, ArghParser, expects_obj
ModuleNotFoundError: No module named 'argh'

[BoboTiG]

Watchmedo is now an extra. To install it and its dependencies, you have to use:

python -m pip install watchdog[watchmedo]

And then argh will be automatically installed.

[bhargavrpatel]

Sounds good, thank you!

[honglei]

argh is not automatically installed for the current version!

https://stackoverflow.com/questions/41268863/difference-between-extras-require-and-install-requires-in-setup-py

but do unittest need it.