This means that if somebody is settings this variable in his .bashrc file for example, in order to have his own manually created virtualenvs use a specific version of python by default (say python2.7), tox will create all venvs with the same python interpreter, whatever the envlist.
I can see three solutions to this:
- don't do anything: maybe add a FAQ entry or note somewhere in the doc or in a troubleshooting session explaining this behaviour
- unset the environment variable before creating the virtualenvs
- create virtualenvs using the --python option and pass it the env (this way the VIRTUALENV_PYTHON isn't used)
I'd go for the third option, thoughts?