Expose virtualenv --no-download somewhere in tox ini

[rogalski]

I work in environment where local PyPI mirror is used. I set non-standard index server in [tox] section of tox.ini file and it works fine when existing virtualenv is reused. When new virtualenv is created, it still attempts to connect to standard PyPI server (see create_environment and install_wheel functions). It spends long time there and eventually get timed out. While virtualenv is still created successfully, long timeout is certainly unexpected behavior.

It could either be done explicitly (something along the lines of virtualenv_custom_args [text], virtualenv_no_download [bool] option), or maybe implicitly (add --no-download when custom index server is defined)

I'd like to get some input before I'll start to work on a PR.

[obestwalter]

@rogalski - interesting. I have the same set up at work and have never noticed that problem. Maybe this is because I have set my pip.conf like this?

[global]
index-url = https://pypi.python.org/simple/
extra-index-url = <company devpi server>

I did that ages ago, before we actually had added the company index to the tox inis, so I will have try this out, how tox behaves with that extra hint for pip.

Edit maybe it is not the same setup after all, as you have a local Pypi mirror and not a devpi server ...

[rogalski]

Using code below in tox.ini seems to do the job:

setenv = 
             VIRTUALENV_DOWNLOAD=0

[asottile]

Duplicates #446 I believe?

[obestwalter]

@asottile I think you wanted to type something else (#446 is about running Travis on Mac), which issue did you mean?

[asottile]

Indeed #448 is the one I was thinking of

[rogalski]

Any extra actions required on my side for removing an incomplete tag?

[obestwalter]

So if I understand it correctly this is indeed a dupe of #448, so I'd say we close this and the discussion how to improve the situation can be followed up there ...

[asottile]

I made a plugin to turn virtualenv's behaviour off entirely: https://github.com/asottile/tox-virtualenv-no-download