@gaborbernat I took the liberty of renaming this PR -- lemme know if that's not OK with you. ;)

Also, please feel free to ping me whenever you're OK with getting feedback/inputs on this.

@pradyunsg still WIP - I would say probably in 2-3 weeks will be ready for review 🤔 need to first add tests for target discovery to reach 100% coverage, do the package boostrapping and activation parts (envs created at this stage are pip-less). Windows 3.7 and 3.8 support is to be done also; but that can wait for after first release.

Opinion: We should reset by opening a new PR for this and closing this one, once we're at a point for reviews, since the force-push messages are annoying IMO. 🤷🏻‍♂️

@gaborbernat You are really brave. Many went this path and nobody returned! ;)

Still, if succeeding on this would be a huge achievement.

Initial encouraging signs, old way:

rm perf -rf; time virtualenv --no-download perf --no-wheel
New python executable in /virtualenv/perf/bin/python
Installing setuptools, pip...
done.
        2.72 real         1.80 user         0.86 sys

New way:

rm perf -rf; time .tox/dev/bin/virtualenv --no-download perf                                                                                                                                                                                                                                        
create with venv /.pyenv/versions/3.7.4/bin/python3.7 -m venv --without-pip /virtualenv/perf
[2019-10-15 19:04:56,429] INFO [/virtualenv/src/virtualenv/interpreters/create/api.py:71]
        0.28 real         0.20 user         0.05 sys

Out of curiosity, is the closure of this PR a good thing or a bad thing? I.e., is the work ready for inclusion in master, or has it been abandoned?

I've got someone helping me out on development, so moved the work over to the feature branch so they can create prs against that. So a great news 👍but we're not there yet release wise, I've been very flooded with other stuff in the last month so did not make much progress, but still continue grinding on it 👍