> Also, with this patch, "./pre-inst-env guix build python-cairocffi"
> fails to build with an error such as:
> 
> OSError: cannot load library 'libxcb.so.1': libxcb.so.1: cannot open
> shared object file: No such file or directory
> 
> Can you try to substitute the invocation of "libxcb.so.1" in
> "xcffib/init.py" to use the full store path and see if that helps?
Ok, I fixed it in a separate patch. That was the reason test were
disabled so that fixed them too.

> Can you change this to use 'pypi-uri' instead?
Any reason why `guix import` doesn't do that by default? I just copied
the output from that command, so I believed it was the way it should
be done.

Anyway, here you have both patches. Please check the message of the
first one, as I'm not fully used to Guix conventions regarding this.
-- 
José Miguel Sánchez García