[Ubuntu] Can't install dependencies

[ag-tafe]

Bug Report

python -m pip install -e .

causes an exception TomlDecodeError("Key name found without value."

To Reproduce

python -m pip install -r test-requirements.txt     # no errors

python -m pip install -e .
ERROR: Exception:
Traceback (most recent call last):
  File "/home/alex/Studying/20111332/mypy/venv/lib/python3.8/site-packages/pip/_internal/cli/base_command.py", line 186, in _main
    status = self.run(options, args)
  File "/home/alex/Studying/20111332/mypy/venv/lib/python3.8/site-packages/pip/_internal/commands/install.py", line 357, in run
    resolver.resolve(requirement_set)
  File "/home/alex/Studying/20111332/mypy/venv/lib/python3.8/site-packages/pip/_internal/legacy_resolve.py", line 177, in resolve
    discovered_reqs.extend(self._resolve_one(requirement_set, req))
  File "/home/alex/Studying/20111332/mypy/venv/lib/python3.8/site-packages/pip/_internal/legacy_resolve.py", line 333, in _resolve_one
    abstract_dist = self._get_abstract_dist_for(req_to_install)
  File "/home/alex/Studying/20111332/mypy/venv/lib/python3.8/site-packages/pip/_internal/legacy_resolve.py", line 265, in _get_abstract_dist_for
    return self.preparer.prepare_editable_requirement(req)
  File "/home/alex/Studying/20111332/mypy/venv/lib/python3.8/site-packages/pip/_internal/operations/prepare.py", line 554, in prepare_editable_requirement
    abstract_dist = _get_prepared_distribution(
  File "/home/alex/Studying/20111332/mypy/venv/lib/python3.8/site-packages/pip/_internal/operations/prepare.py", line 95, in _get_prepared_distribution
    abstract_dist.prepare_distribution_metadata(finder, build_isolation)
  File "/home/alex/Studying/20111332/mypy/venv/lib/python3.8/site-packages/pip/_internal/distributions/sdist.py", line 33, in prepare_distribution_metadata
    self.req.load_pyproject_toml()
  File "/home/alex/Studying/20111332/mypy/venv/lib/python3.8/site-packages/pip/_internal/req/req_install.py", line 512, in load_pyproject_toml
    pyproject_toml_data = load_pyproject_toml(
  File "/home/alex/Studying/20111332/mypy/venv/lib/python3.8/site-packages/pip/_internal/pyproject.py", line 75, in load_pyproject_toml
    pp_toml = toml.load(f)
  File "/usr/share/python-wheels/toml-0.10.0-py2.py3-none-any.whl/toml/decoder.py", line 134, in load
    return loads(f.read(), _dict, decoder)
  File "/usr/share/python-wheels/toml-0.10.0-py2.py3-none-any.whl/toml/decoder.py", line 186, in loads
    raise TomlDecodeError("Key name found without value."
toml.decoder.TomlDecodeError: Key name found without value. Reached end of line. (line 133 column 2 char 4066)

Expected Behavior
Dependencies are installed.

Actual Behavior
Exception raised (see above).

Your Environment

• Mypy version used: Mypy 1.12
• Mypy command-line flags:
• Mypy configuration options from mypy.ini (and other config files):
• Python version used: Python 3.8

[JelleZijlstra]

The error is happening from within pip, your stack trace suggests you are using an unusual system for Python packaging (never seen /usr/share/python-wheels before), and you are using an unsupported version of Python (3.8). The version of the toml library that shows up in the stack trace was released in 2020.

Most likely you need to upgrade your packaging toolchain (i.e., use a newer version of pip), because some mypy dependency is using TOML features that aren't supported in this old library.

[ag-tafe]

.github/workflows/test.yml has the following lines (see below). So Python 3.8 is actually not supported?

# Make sure to run mypyc compiled unit tests for both
        # the oldest and newest supported Python versions
        - name: Test suite with py38-ubuntu, mypyc-compiled
          python: '3.8'
          arch: x64
          os: ubuntu-latest
          toxenv: py
          tox_extra_args: "-n 4"
          test_mypyc: true

[JelleZijlstra]

I believe mypy still supports 3.8 for one more release. However, we do not and cannot support old versions of pip (which is likely what you are using).

[ag-tafe]

Thank you for your help. I've updated Python to version 3.10.15 and pip to version 24.2
All dependencies installed without an error. Now I get "FileNotFound" when trying to run tests:

(venv) alex@alexE5470:~/Studying/20111332/mypy$ python3 runtests.py
Traceback (most recent call last):
  File "/home/alex/Studying/20111332/mypy/runtests.py", line 171, in <module>
    main()
  File "/home/alex/Studying/20111332/mypy/runtests.py", line 153, in main
    proc = start_background_cmd("lint")
  File "/home/alex/Studying/20111332/mypy/runtests.py", line 118, in start_background_cmd
    proc = subprocess.Popen(cmd, stderr=subprocess.STDOUT, stdout=subprocess.PIPE)
  File "/usr/lib/python3.10/subprocess.py", line 971, in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
  File "/usr/lib/python3.10/subprocess.py", line 1863, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'pre-commit'

[JelleZijlstra]

We fixed this recently (#17911). For now, you can manually pip install pre-commit.

[ag-tafe]

Yay! It worked. Thank you!

Some useful links I used:

Update Python to 3.10
https://www.itsupportwale.com/blog/how-to-upgrade-to-python-3-10-on-ubuntu-18-04-and-20-04-lts/

Update virtual environment
https://www.geeksforgeeks.org/upgrade-python-virtual-environment-to-latest-version/