tox auto-provisioning not working

[johannesloibl]

Issue

When specifying

[tox]
requires =
    tox<4

and running this command with a tox version > 4.0.0, I expect that tox will provision a .tox/.tox directory with a version < 4.0.0.
But the created venv .tox does not get a tox installation. See console.

Environment

OS: Win 10, 64-bit
Python 3.9.13
tox 4.0.2

Output of running tox

Output of tox -e py39-dev:

C:\git\foo>tox -e py39-dev
ROOT: will run in automatically provisioned tox, host C:\Python39\python.exe is missing [requires (has)]: tox<4 (4.0.2)
ROOT: provision> .tox\.tox\Scripts\python.exe -m tox -e py39-dev
C:\git\foo\.tox\.tox\Scripts\python.exe: No module named tox

[gaborbernat]

Can't replicate. Can you provide a reproducible here?

[johannesloibl]

Trying to reproduce right now with a minimal example, but that one seems to work.
I saw a similar issue on one of our Jenkins nodes that failed, maybe this gives you more information about what could have happened:

Seems like somehow for projects that transition between version 3 and 4, tox gets confused about which .tox directory to use, which is ending up in an endless adding up of ".tox" 😅

[gaborbernat]

Sadly that's not enough to reproduce 😆 but I see what you mean.

[johannesloibl]

Alright, now i got it:

[tox]
requires =
    tox<4

[testenv]
basepython = python3
deps =
    pytest

If you execute this within an environment that has tox 4.0.2 installed, you will see the error.
So autoprovisioning for downgrade is not working.

[johannesloibl]

[tox]
requires =
    tox<4

[testenv]
basepython = python3

Executing this raises another error:

Shall i create another ticket for that or is it a user error?^^

[domdfcoding]

I can reproduce with the following tox.ini config:

[tox]
requires = numpy

[testenv]
skip_install = true
deps = -r{toxinidir}/tests/requirements.txt
commands =
    python --version

tests/requirements.txt is an empty file.

The output is:

$ tox
ROOT: will run in automatically provisioned tox, host /tmp/tox-issue/venv/bin/python3 is missing [requires (has)]: numpy
ROOT: provision> .tox/.tox/bin/python -m tox
/tmp/tox-issue/.tox/.tox/bin/python: No module named tox

If I remove the deps option from [testenv] it provisions (although in reality I need the dependencies installed for my tests to run):

$ tox
ROOT: will run in automatically provisioned tox, host /tmp/tox-issue/venv/bin/python3 is missing [requires (has)]: numpy
ROOT: install_deps> python -I -m pip install numpy 'tox>=4.0'
ROOT: provision> .tox/.tox/bin/python -m tox
py: commands[0]> python --version
Python 3.8.10
  py: OK (0.15=setup[0.14]+cmd[0.00] seconds)
  congratulations :) (0.48 seconds)

It seems that it's trying to install tests/requirements.txt into the root testenv, when it isn't required there (and wasn't installed there by tox 3) and not installing tox>=4.0