Error when running pypi2nix command

[OmnipotentEntity]

From a nix-shell -p pypi2nix pkg-config SDL freetype

% pypi2nix --version
2.0.4
% pypi2nix -e katrain
INFO: pypi2nix v2.0.4 running ...
INFO: Downloading wheels and creating wheelhouse ...
INFO: Downloading runtime requirements
Collecting katrain
  Downloading KaTrain-1.2.2.tar.gz (57.4 MB)
  Saved /run/user/1000/tmplkx8jjyf/download/KaTrain-1.2.2.tar.gz
Collecting wheel
  Downloading wheel-0.34.2.tar.gz (58 kB)
  Saved /run/user/1000/tmplkx8jjyf/download/wheel-0.34.2.tar.gz
Collecting setuptools
  Downloading setuptools-49.1.0.zip (2.2 MB)
  Saved /run/user/1000/tmplkx8jjyf/download/setuptools-49.1.0.zip
Collecting pygame
  Downloading pygame-1.9.6.tar.gz (3.2 MB)
  Saved /run/user/1000/tmplkx8jjyf/download/pygame-1.9.6.tar.gz
    ERROR: Command errored out with exit status 1:
     command: /nix/store/svcijfkigbwfpmfrxfyg1a93g6pjfr3p-python3-3.7.6-env/bin/python3.7 -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/run/user/1000/tmplkx8jjyf/pip-download-lucjl3ij/pygame/setup.py'"'"'; __file__='"'"'/run/user/1000/tmplkx8jjyf/pip-download-lucjl3ij/pygame/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base /run/user/1000/tmplkx8jjyf/pip-download-lucjl3ij/pygame/pip-egg-info
         cwd: /run/user/1000/tmplkx8jjyf/pip-download-lucjl3ij/pygame/
    Complete output (20 lines):

    WARNING, No "Setup" File Exists, Running "buildconfig/config.py"
    Using UNIX configuration...

    /bin/sh: sdl-config: command not found
    /bin/sh: sdl-config: command not found
    /bin/sh: sdl-config: command not found
    /bin/sh: pkg-config: command not found
    /bin/sh: pkg-config: command not found
    /bin/sh: pkg-config: command not found
    /bin/sh: freetype-config: command not found
    /bin/sh: freetype-config: command not found
    /bin/sh: freetype-config: command not found

    Hunting dependencies...
    WARNING: "sdl-config" failed!
    WARNING: "pkg-config freetype2" failed!
    WARNING: "freetype-config" failed!
    Unable to run "sdl-config". Please make sure a development version of SDL is installed.
    ----------------------------------------
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.
WARNING: You are using pip version 20.0.dev0; however, version 20.1.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
ERROR: Collecting katrain
ERROR:   Downloading KaTrain-1.2.2.tar.gz (57.4 MB)
ERROR:   Saved /run/user/1000/tmplkx8jjyf/download/KaTrain-1.2.2.tar.gz
ERROR: Collecting wheel
ERROR:   Downloading wheel-0.34.2.tar.gz (58 kB)
ERROR:   Saved /run/user/1000/tmplkx8jjyf/download/wheel-0.34.2.tar.gz
ERROR: Collecting setuptools
ERROR:   Downloading setuptools-49.1.0.zip (2.2 MB)
ERROR:   Saved /run/user/1000/tmplkx8jjyf/download/setuptools-49.1.0.zip
ERROR: Collecting pygame
ERROR:   Downloading pygame-1.9.6.tar.gz (3.2 MB)
ERROR:   Saved /run/user/1000/tmplkx8jjyf/download/pygame-1.9.6.tar.gz
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Error: While trying to run the command something went wrong.

All of sdl-config, pkg-config, and freetype-config are in my path, which means that the shell launched by the python executable is not inheriting PATH properly. I'm not aware of an easy way to work around this.

[OmnipotentEntity]

The -E flag is a thing.

[OmnipotentEntity]

Now I'm getting a duplicate of #448 which is to be expected I suppose?