macOS Big Sur v11.2: pip install gftools works, but --editable install fails

[eliheuer]

I'm trying to get gftools working on a 2020 M1 Mac Mini (Big Sur v11.2) Python v3.9.2, and having issues.

Following the advice here... https://github.com/googlefonts/gftools/issues/298 https://github.com/googlefonts/gftools/pull/300 I got gftools working on Big Sur 11.2 by installing ttfautohint manually, then brew install libgit2, and it works when using pip install gftools.

However, I want to make some PRs back to gftools, and when I try to install in --editable mode I get the old ttfautohint-py error:

Requirement already satisfied: babelfont in /Users/eli/Py/repos/babelfont/lib (from gftools==0.7.1.dev2+g3d633b9) (2.0.3.dev5+ge30aba5)
ERROR: Could not find a version that satisfies the requirement `ttfautohint-py` (from `gftools`)
ERROR: No matching distribution found for `ttfautohint-py`

Please let me know if anyone has been able to get gftools working in --editable mode on Big Sur with a M1 computer.