Error when running pypi2nix command

[Prag066]

Description

<detailed description of error # Traceback

% pypi2nix --version
% pypi2nix --python-version python37 --requirements requirements.txt --default-overrides --setup-requires setuptools-scm -E libxml2 -E libxslt -E libjpeg -E postgresql -E libffi -E openssl
Looking in links: file:///run/user/1000/tmpl_r7tzpf/download, file:///run/user/1000/tmpl_r7tzpf/wheel
Processing /run/user/1000/tmpl_r7tzpf/download/setuptools-49.1.3.zip
Processing /run/user/1000/tmpl_r7tzpf/download/wheel-0.34.2.tar.gz
Processing /run/user/1000/tmpl_r7tzpf/download/setuptools_scm-4.1.2.tar.gz
  Installing build dependencies: started
  Installing build dependencies: finished with status 'done'
  Getting requirements to build wheel: started
  Getting requirements to build wheel: finished with status 'done'
    Preparing wheel metadata: started
    Preparing wheel metadata: finished with status 'done'
Building wheels for collected packages: setuptools-scm
  Building wheel for setuptools-scm (PEP 517): started
  Building wheel for setuptools-scm (PEP 517): finished with status 'done'
  Created wheel for setuptools-scm: filename=setuptools_scm-4.1.2-cp37-none-any.whl size=27595 sha256=ec91a4f97e56be733c63f556e50921e65bcf76070f33535a2ce7449f793174a9
  Stored in directory: /run/user/1000/tmpl_r7tzpf/cache/wheels/6c/51/45/6ec029add5fb39575ceafef9a01ec75f8cf9bdb8c7431545d0
Successfully built setuptools-scm
Building wheels for collected packages: setuptools, wheel
  Building wheel for setuptools (setup.py): started
  Building wheel for setuptools (setup.py): finished with status 'done'
  Created wheel for setuptools: filename=setuptools-49.1.3-cp37-none-any.whl size=789533 sha256=03e4d8dae5a2602e3d70b48f971e6ef8b07c6bc1590bf23f63c9880f2d001245
  Stored in directory: /run/user/1000/tmpl_r7tzpf/cache/wheels/ba/d6/21/50e39e5ea5e7a8a8690e76cfea1f9bb318d461b38f92754337
  Building wheel for wheel (setup.py): started
  Building wheel for wheel (setup.py): finished with status 'done'
  Created wheel for wheel: filename=wheel-0.34.2-py2.py3-none-any.whl size=26339 sha256=1b90c86bfeed1522d12492ae297c568b475766f75f88550ca89f75381a1be078
  Stored in directory: /run/user/1000/tmpl_r7tzpf/cache/wheels/23/bd/04/cb9d3e053ef5fa937cfcc6e97263bd9e428056fff76ecfb622
Successfully built setuptools wheel
Installing collected packages: setuptools, wheel, setuptools-scm
Successfully installed setuptools-49.1.3 setuptools-scm-4.1.2 wheel-0.34.2
Collecting django==3.0.6
  Downloading Django-3.0.6.tar.gz (9.1 MB)
  Saved /run/user/1000/tmpl_r7tzpf/download/Django-3.0.6.tar.gz
Collecting Babel==2.8.0
  Downloading Babel-2.8.0.tar.gz (8.4 MB)
  Saved /run/user/1000/tmpl_r7tzpf/download/Babel-2.8.0.tar.gz
Collecting beautifulsoup4==4.9.0
  Downloading beautifulsoup4-4.9.0.tar.gz (368 kB)
  Saved /run/user/1000/tmpl_r7tzpf/download/beautifulsoup4-4.9.0.tar.gz
Collecting lxml==4.5.0
  Downloading lxml-4.5.0.tar.gz (4.5 MB)