Gábor Boskovits <boskovits@gmail.com> writes:

> Regarding the PyPi tarball I was trying like:
>
> (method url-fetch)
>        (uri (pypi-uri "networkx" version))
>
> with version "2.0"
>
> and got:
> Starting download of
> /gnu/store/7m7r6dj9vc4mz53a4p296nan1nf8h2d2-networkx-2.0.tar.gz
> From https://pypi.io/packages/source/n/networkx/networkx-2.0.tar.gz...
> following redirection to `
> https://pypi.org/packages/source/n/networkx/networkx-2.0.tar.gz'...
> following redirection to `
> https://files.pythonhosted.org/packages/source/n/networkx/networkx-2.0.tar.gz'.
> ..
> ERROR: download failed "
> https://files.pythonhosted.org/packages/source/n/networkx/networkx-2.0.tar.gz"
> 404 "Not Found"

This is because the PyPi archive is only available as a "zipball".
"pypi-uri" takes an optional argument for specifying file extension.

I went ahead and changed the source URI and added a Python2 variant --
not using git-fetch allowed us to also remove the 'reset-permissions'
phase.  Changes below.  Thank you!