Source packages not getting included in `mkPoetryEnv`

[Smaug123]

Describe the issue

It appears that git source packages incorrectly fail to end up in the mkPoetryEnv environment.

Additional context

I'm attempting to build Stable Diffusion, via my fork; flake at https://github.com/invoke-ai/InvokeAI/blob/d87faddfcf37b3d44a04ae08e05554e78cac4a2b/flake.nix

At runtime, Stable Diffusion fails to start, with ModuleNotFoundError: No module named 'taming'. taming comes from taming-transformers, which is in my poetry.lock; it's obtained by source.

The resulting Python environment's ls -la /nix/store/4li87c09d8fzddzib68rhkx70wmkk94n-python3-3.9.13-env/lib/python3.9/site-packages contains a dist-info for taming-transformers (specifically taming_transformers-0.0.1.dist-info -> /nix/store/2q3s7rk41rxphfm8ily7a8mr0qrpvxv6-python3.9-taming-transformers-0.0.1/lib/python3.9/site-packages/taming_transformers-0.0.1.dist-info), but it does not contain the source anywhere:

> find /nix/store/4li87c09d8fzddzib68rhkx70wmkk94n-python3-3.9.13-env -name '*taming*'
/nix/store/4li87c09d8fzddzib68rhkx70wmkk94n-python3-3.9.13-env/lib/python3.9/site-packages/taming_transformers-0.0.1.dist-info

By contrast, a manually-created virtual environment has the source, checked out into venv/src/taming-transformers.

[Smaug123]

This was actually an upstream bug; it's fixed by CompVis/taming-transformers#173, if they ever decide to merge it.