Error when running pypi2nix command

[asfishman]

Description

<detailed description of error # Traceback

% pypi2nix --version
1.8.1
% pypi2nix -V 3 -r req
warning: ignoring the user-specified setting 'show-trace', because it is a restricted setting and you are not a trusted user

Collecting argparse>=1.2 (from -r /run/user/1000/pypi2nix/c775c87d79df954709ab162e9dd1a13b/db83772990a320fafc829b979559a7b4.txt (line 1))

  Downloading https://files.pythonhosted.org/packages/18/dd/e617cfc3f6210ae183374cd9f6a26b20514bbb5a792af97949c5aacddf0f/argparse-1.4.0.tar.gz (70kB)

Collecting cerberus (from -r /run/user/1000/pypi2nix/c775c87d79df954709ab162e9dd1a13b/db83772990a320fafc829b979559a7b4.txt (line 2))

  Downloading https://files.pythonhosted.org/packages/90/a7/71c6ed2d46a81065e68c007ac63378b96fa54c7bb614d653c68232f9c50c/Cerberus-1.3.2.tar.gz (52kB)

Collecting empy>=3.3 (from -r /run/user/1000/pypi2nix/c775c87d79df954709ab162e9dd1a13b/db83772990a320fafc829b979559a7b4.txt (line 3))

  Downloading https://files.pythonhosted.org/packages/3b/95/88ed47cb7da88569a78b7d6fb9420298df7e99997810c844a924d96d3c08/empy-3.3.4.tar.gz (62kB)

Collecting jinja2>=2.8 (from -r /run/user/1000/pypi2nix/c775c87d79df954709ab162e9dd1a13b/db83772990a320fafc829b979559a7b4.txt (line 4))

  Downloading https://files.pythonhosted.org/packages/d8/03/e491f423379ea14bb3a02a5238507f7d446de639b623187bccc111fbecdf/Jinja2-2.11.1.tar.gz (258kB)

Collecting numpy>=1.13 (from -r /run/user/1000/pypi2nix/c775c87d79df954709ab162e9dd1a13b/db83772990a320fafc829b979559a7b4.txt (line 5))

  Downloading https://files.pythonhosted.org/packages/40/de/0ea5092b8bfd2e3aa6fdbb2e499a9f9adf810992884d414defc1573dca3f/numpy-1.18.1.zip (5.4MB)

Collecting pandas>=0.21 (from -r /run/user/1000/pypi2nix/c775c87d79df954709ab162e9dd1a13b/db83772990a320fafc829b979559a7b4.txt (line 6))

  Downloading https://files.pythonhosted.org/packages/02/c3/e8c56de02d6c52f8541feca2fd77117e8ae4956f7b3e5cdbed726624039b/pandas-1.0.1.tar.gz (4.9MB)

    Complete output from command python setup.py egg_info:

    Traceback (most recent call last):

      File "<string>", line 1, in <module>

      File "/run/user/1000/pypi2nix/cache/pip/pandas/setup.py", line 757, in <module>

        ext_modules=maybe_cythonize(extensions, compiler_directives=directives),

      File "/run/user/1000/pypi2nix/cache/pip/pandas/setup.py", line 515, in maybe_cythonize

        raise RuntimeError("Cannot cythonize without Cython installed.")

    RuntimeError: Cannot cythonize without Cython installed.

    

    ----------------------------------------

Command "python setup.py egg_info" failed with error code 1 in /run/user/1000/pypi2nix/cache/pip/pandas/

You are using pip version 9.0.1, however version 20.0.2 is available.

You should consider upgrading via the 'pip install --upgrade pip' command.