chore: tox toml by henryiii · Pull Request #1033 · pypa/build

henryiii · 2026-04-13T16:42:41Z

Description

This is an attempt to convert the tox.ini to tox.toml. I started
by pointing copilot at the tox documentation for configuration.
I then asked it to use a generative list, telling it it was okay to reverse
the order ...-min to min-....

Still need to:

Check the minimum tox version this requires (update: used last tox-uv that supported 3.9)
Consider putting it in pyproject.toml

🤖 I'm manually using Linux's Assisted-by trailer for comments. Used Copilot:claude-sonnet-4.6

Changelog

Added changelog fragment: docs/changelog/<pr_number>.<type>.rst
- Types: feature, bugfix, doc, removal, misc
- Example: 123.feature.rst containing Add custom backend support - by :user:`yourname`

Checklist

Tests pass locally (tox)
Code follows project style (tox -e fix)
Type checks pass (tox -e type)
Documentation builds (tox -e docs)

henryiii · 2026-04-13T17:47:52Z

          flags: tests
          env_vars: PYTHON
-          name: ${{ matrix.py }} - ${{ matrix.os }}
+          name: ${{ matrix.py }} - ${{ matrix.os }} - ${{ matrix.tox-target }}


Unrelated change, but seems like this is needed, otherwise two jobs have the same name.

henryiii · 2026-04-13T17:49:03Z

+TEST_STATUS_DIR = "{envtmpdir}"
+
+[env_base.min]
+factors = [["3.9", "3.10", "3.11", "3.12", "3.13", "3.14", "pypy3.9", "pypy3.10", "pypy3.11"]]


I don't think I can use range here.

Also, I don't like that we have to make this list so many times, it would be nice if I could reuse it somehow. But maybe it's easy enough to update with AI. ¯\_(ツ)_/¯

abitrolly · 2026-04-22T08:45:33Z

@henryiii did tox get a decent CLI UX with the new config format recently? Like show the commands I can run without learning about tox.ini and stuff?

gaborbernat · 2026-04-22T14:41:52Z

tox l always did that 🤔

henryiii · 2026-04-22T14:48:14Z

Yes, tox list (or I guess tox l, that's a bit closer in typing to nox -l, I guess!) is great.

abitrolly · 2026-04-22T18:17:53Z

It takes sooo long. I couldn't wait.

# time tox l
ROOT: will run in automatically provisioned tox, host /usr/local/bin/python3.14 is missing [requires (has)]: tox-uv
ROOT: install_deps> python -I -m pip install tox tox-uv 'tox>=4.22' 'virtualenv>=20.0.34'
^C
real	0m8.066s
user	0m1.767s
sys	0m0.184s

It appears it can not just run itself to show help and needs to create virtualenv. Or no, the rabbit hole. I am not going to get down there. :D

subcommands:
  tox command to execute (by default legacy)

  {run,r,run-parallel,p,depends,de,man,list,l,devenv,d,schema,config,c,quickstart,q,exec,e,legacy,le}
    run (r)                   run environments
    run-parallel (p)          run environments in parallel

I made a fix to remove that argparse "feature" 10 years ago, but didn't post it anywhere.

gaborbernat · 2026-04-22T19:22:08Z

It appears it can not just run itself to show help and needs to create virtualenv.

Mean, you have an old outdated version of the tool that doesn't support the new features; so needs to install a newer version of itself following https://tox.wiki/en/4.53.0/explanation.html#auto-provisioning, the speed here will depend a lot on your network.

abitrolly · 2026-04-23T01:18:56Z

@gaborbernat it was pip install tox in a clear Python container.

Downloading tox-4.53.0-py3-none-any.whl (212 kB)

But I can't repeat that anymore. I guess it was its local state in mounted dir that had to be updated.

Convert the INI-format tox configuration to the recommended TOML format (tox.toml). The environment list and all behaviours are preserved; tox list output is identical before and after. Key translation notes: - [tox] top-level keys → bare top-level keys - [testenv] → [env_run_base] - [testenv:name] → [env.name] - set_env → TOML subtable / inline table; empty INI value → `{}` - commands → list of lists; `{posargs:-n auto}` → replace/default inline table - basepython → base_python, changedir → change_dir - Generative section `[testenv:{py314,...}-min]` (INI-only feature) expanded into nine explicit `[env.XXX-min]` sections Assisted-by: Copilot:claude-sonnet-4.6 Signed-off-by: Henry Schreiner <henryfs@princeton.edu>

Replace nine identical `[env.XXX-min]` sections with a single `[env_base.min]` template. The env_base factors mechanism generates min-py314, min-py313, ... (prefix ordering is required by TOML's env_base, which always prepends the template name). env_list uses a product dict to keep the min variants concise. coverage.depends is updated to the new names. Assisted-by: Copilot:claude-sonnet-4.6 Signed-off-by: Henry Schreiner <henryfs@princeton.edu>

Signed-off-by: Henry Schreiner <henryfs@princeton.edu>

pip 23.2 fails on Python 3.15 with: TypeError: Can't instantiate abstract class WheelDistribution without an implementation for abstract method 'locate_file' WheelDistribution.locate_file() was added in pip 25.0 (January 2025). Assisted-by: Copilot:claude-sonnet-4.6 Signed-off-by: Henry Schreiner <henryfs@princeton.edu>

pip 25.0/25.1 fail on Python 3.15 with: AttributeError: module 'typing' has no attribute 'no_type_check_decorator' typing.no_type_check_decorator was removed in Python 3.15. pip's vendored typing_extensions still referenced it until pip 25.3. Assisted-by: Copilot:claude-sonnet-4.6 Signed-off-by: Henry Schreiner <henryfs@princeton.edu>

Copilot

Pull request overview

This PR migrates the project’s tox configuration from tox.ini to tox.toml, updating CI, packaging, and docs to reference the new config file.

Changes:

Replace tox.ini with a new tox.toml tox configuration (including generated env lists and tox-uv integration).
Update CI workflows and release/docs references to use the new tox env naming and config file.
Adjust packaging/test fixtures to include tox.toml in sdists and update constraints for newer Python/pip.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tox.toml	New tox TOML configuration replacing the removed `tox.ini`.
tox.ini	Removed legacy tox INI configuration.
tests/test_self_packaging.py	Updates sdist expectations to include `tox.toml` instead of `tox.ini`.
tests/constraints.txt	Updates pip constraints for newer Python versions.
pyproject.toml	Updates flit sdist include list to ship `tox.toml`.
docs/development/release.rst	Updates documentation reference from `tox.ini` to `tox.toml`.
docs/development/contributing.rst	Updates contributor docs with new tox invocation examples.
.pre-commit-config.yaml	Removes `tox-ini-fmt` hook since `tox.ini` is removed.
.github/workflows/reusable-pytest.yml	Adjusts tox env selection logic to match the new env naming scheme.
.github/workflows/reusable-change-detection.yml	Updates change-detection filters to track `tox.toml` instead of `tox.ini`.

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Signed-off-by: Henry Schreiner <henryfs@princeton.edu>

gaborbernat reviewed Apr 13, 2026

View reviewed changes