--pypi-mirror not respected during virtualenv creation after 2018.10.13

[JacobHenner]

On Windows, versions of Pipenv > 2018.10.13 attempt to connect to https://pypi.org during virtualenv creation, even if --pypi-mirror is specified. This is a regression from 2018.10.13.

I've compared the network activity of 2018.10.13 and 11.14/11.26. For the latter two, connection attempts to pypi.org are made regardless of whether --pypi-mirror is specified. With 10.13, no such attempts are made.

This issue causes inconsistent timeouts and failures when a user is behind a firewall with a drop rule affecting pypi.org.

[jxltom]

Which command are you exactly using, pipenv --python <x.y.z> --pypi-mirror?

This pypi mirror should be passed to virtualenv creation by

pipenv/pipenv/cli/command.py

Lines 199 to 208 in d4d54ee

	# --two / --three was passed…
	if (state.python or state.three is not None) or state.site_packages:
	ensure_project(
	three=state.three,
	python=state.python,
	warn=True,
	site_packages=state.site_packages,
	pypi_mirror=state.pypi_mirror,
	clear=state.clear,
	)

[JacobHenner]

I've tracked down the issue to a bug in vistir, which is preventing PIP_INDEX_URL from being set correctly before virtualenv is run. I'll resolve and submit a PR shortly.

[JacobHenner]

Caused by sarugaku/vistir#55, which likely affects all instances of vistir.misc.run() which depend upon environment variables being specified as a parameter (only one instance with env specified).

[jxltom]

👍