ModuleNotFoundError: No module named 'tomllib'

[LostInDarkMath]

Describe the bug
When I run tests in Travis CI against Python3.11-dev I get the following error:

$ coverage run --branch pedantic/tests/tests_main.py

Traceback (most recent call last):

  File "/home/travis/virtualenv/python3.11-dev/bin/coverage", line 5, in <module>

    from coverage.cmdline import main

    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

  File "/home/travis/virtualenv/python3.11-dev/lib/python3.11/site-packages/coverage/__init__.py", line 15, in <module>

    from coverage.control import Coverage, process_startup

    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

  File "/home/travis/virtualenv/python3.11-dev/lib/python3.11/site-packages/coverage/control.py", line 20, in <module>

    from coverage.collector import Collector, CTracer

    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

  File "/home/travis/virtualenv/python3.11-dev/lib/python3.11/site-packages/coverage/collector.py", line 10, in <module>

    from coverage.config import CoverageConfig

    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

  File "/home/travis/virtualenv/python3.11-dev/lib/python3.11/site-packages/coverage/config.py", line 16, in <module>

    from coverage.tomlconfig import TomlConfigParser, TomlDecodeError

    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

  File "/home/travis/virtualenv/python3.11-dev/lib/python3.11/site-packages/coverage/tomlconfig.py", line 16, in <module>

    import tomllib      # pylint: disable=import-error

    ^^^^^^^^^^^^^^

ModuleNotFoundError: No module named 'tomllib'

To Reproduce
How can we reproduce the problem? Please be specific. Don't link to a failing CI job. Answer the questions below:

1. What version of Python are you using? Python 3.11.0a3+
2. What version of coverage.py shows the problem? 6.4
3. What code shows the problem? Does not matter.
4. What commands did you run? coverage run --branch pedantic/tests/tests_main.py

Expected behavior
Run tests with coverage.

Additional context
Nothing.

[nedbat]

Hmm, we switched to use tomllib since it's in 3.11, but we check for version >= 3.11, and tomllib was added in 3.11.0a7. You are running 3.11.0a3+. Can you update to a more recent 3.11? 3.11.0b2 is now out.

[LostInDarkMath]

Thank you for your fast reply! Unfortunately, this in the hands of Travis CI. So I cannot do anything and I'll wait for the newer version at Travis.

[nedbat]

I fixed the check for tomllib to be more precise in commit 3a23d8a. If you install coverage from GitHub, it should work for you.

[nedbat]

This is now released as part of coverage 6.4.1.

[hugovk]

Unfortunately, this in the hands of Travis CI. So I cannot do anything and I'll wait for the newer version at Travis.

I've asked Travis CI to update their 6-month-old 3.11-dev development branch:

https://travis-ci.community/t/update-python-3-11-dev/13039

[hugovk]

And Travis CI have now updated 3.11-dev and it now points to:

3.11.0b3+ (heads/3.11:fae93ab, Jun  3 2022, 16:03:01) [GCC 9.3.0]

🎉

https://travis-ci.community/t/update-python-3-11-dev/13039/2?u=hugovk

[LostInDarkMath]

Thank you very much @hugovk!