per https://sourmash.readthedocs.io/en/latest/developer.html,

• it's not clear that the "general instructions" come after/are an ALTERNATIVE to the mamba install stuff
• the mamba install stuff doesn't actually install tox, although tox-conda is installed? weird. Anyway you need to do a python -m pip install tox
• we should probably explicitly suggest mambaforge... because we like mambaforge...

also: personally, I'm not a huge fan of the make test running tox, because it takes a lot of extra time vs just running pytest.

more maybe later.