hexop

I ran into the same problem, the solution is to install the python 3 development files, it should be called `python3-dev` or `python3-devel`. I also had to install `libsub-devel` and...

I am running into the same problem, I have submitted a pull request. Meanwhile, you can use [my fork](https://github.com/hexop/openconnect-sso) if you want to update nixpkgs

It seems to be broken upstream, I am not sure how to have a workaround right now (my nix-fu isn't great either) I am now following [this issue](https://github.com/nix-community/poetry2nix/pull/736) and hoping...

I've updated my fork by removing the dev dependency coverage_enable_subprocess, and now it seems to build with the latest nixpkgs. This is available [on this branch](https://github.com/hexop/openconnect-sso/tree/poetry-workaround) which you can use...