Issue

(note: This is another one to consider very low-priority, like #3649. Once again, I'm reporting so it's written down somewhere)

The following was my first pass at writing a tox.toml file:

[tox]
requires = ["tox>=4"]
env_list = ["lint"]

[env.lint]
deps =
    mypy
    ruff
commands =
    ruff check {posargs}
    mypy src/ci_status

It's clearly invalid. However, running --help (which I don't believe should have anything to do with tox.toml or any tox configuration file) spits out the following error:

❯ tox --help
ROOT: HandledError| TomlTox failed loading /home/stephenfin/Code/foo/tox.toml due to Invalid value (at line 6, column 7)

Using the bash autocomplete provided by my distro package is also broken, as seen below, but I think that is not managed by tox (in-tree at least) and presumably is parsing the output of some other command.

❯ tox -e  
6,
7)
ALL
(at
column
due
failed
HandledError|
/home/stephenfin/Code/foo/tox.toml
Invalid
line
loading
ROOT:
to
TomlTox
value

Environment

Fedora 43

Output of running tox

4.35.0 from /usr/lib/python3.14/site-packages/tox/__init__.py

Minimal example

See above.