How do I map the pyenv to tox if I use tox in poetry

[ralf-kowatsch]

My setup is

pyproject.tom
`
[tool.tox]
env_list = ["3.11.16", "3.12.14", "coverage-report"] # We have to specify the python versions explicitly to get around acivating multiple versions in the shim.

[tool.tox.env_run_base]
pass_env = ["*"]
package = "editable"
deps = ["coverage[toml]", "unittest-xml-reporting", "python-dotenv"]
commands = [
["coverage", "run", "--data-file=.coverage.{envname}"],
]

[tool.tox.env.coverage-report]
depends = ["3.11.15", "3.12.13"]
skip_install = true
pass_env = ["*"]
deps = ["coverage[toml]", "unittest-xml-reporting"]
commands = [
["coverage", "combine"],
["coverage", "xml", "-o", "coverage.xml"]
]
`

and a Makefile
`
PYTHON_VERSION := $(shell cat .python-version)
PYENV_VERSIONS := 3.14.7 3.12.14 3.11.16 3.9.25

all: setup_environment

clean:
poetry run pre-commit uninstall
git clean -fdX

setup_environment: check
pyenv install $(PYENV_VERSIONS) --skip-existing
&& pyenv global $(PYENV_VERSIONS)
&& poetry env use $(PYTHON_VERSION)
&& poetry install
&& poetry run pre-commit install

check: pyenv_exists poetry_exists is_git

pyenv_exists: ; @which pyenv > /dev/null

poetry_exists: ; @which poetry > /dev/null

is_git: ; @git rev-parse --git-dir > /dev/null
`

It seems that py311,py312 in env_list does not work, tox cant find the python interpreter, falls back to the default interpreter and does not choose the expected python version. What do I do wrong?

[tayfuryldz]

env_list names are also how tox infers the Python interpreter. The important part here is that 3.11.16 / 3.12.14 are not good environment names for selecting those patch releases.

For the normal test matrix, name the environments by the Python factor:

[tool.tox]
env_list = ["py311", "py312", "coverage-report"]

[tool.tox.env_run_base]
package = "editable"
deps = ["coverage[toml]", "unittest-xml-reporting", "python-dotenv"]
commands = [
  ["coverage", "run", "--data-file=.coverage.{envname}"],
]

[tool.tox.env.coverage-report]
depends = ["py311", "py312"]
skip_install = true
deps = ["coverage[toml]", "unittest-xml-reporting"]
commands = [
  ["coverage", "combine"],
  ["coverage", "xml", "-o", "coverage.xml"],
]

Then make those interpreters visible to the process running tox. With pyenv that means having the relevant versions installed and selected so its shims can resolve python3.11 and python3.12 (for example via the project's .python-version). Poetry does not need to choose each tox interpreter; it only needs an environment from which tox itself can run.

On current tox, interpreter resolution starts with the Python factor in the environment name (py311, py312, etc.). There is also base_python_file (added in tox 4.51) for environments without a Python factor, if you want one of those environments to read a version from a .python-version-style file.

One other mismatch in the example: coverage-report.depends currently names 3.11.15 and 3.12.13, while env_list names 3.11.16 and 3.12.14. depends should refer to the actual tox environment names; using py311 / py312 in both places avoids that drift.