Generate report (mypy.xml) fails when running mypy in parallel with another job

[lukin0110]

Bug Report

In pyproject.toml I've configured mypy and coverage to generate their reports in the same directory: reports. In Gitlab CI I'm running 2 jobs in parallel to run mypy and coverage. Sometimes the mypy jobs fails.

To Reproduce

Run mypy and coverage in parallel in Gitlab CI.

Expected Behavior

Always generate the report in reports/mypy.xml.

Actual Behavior

Traceback (most recent call last):
  File "/opt/my-package-env/bin/mypy", line 8, in <module>
    sys.exit(console_entry())
             ^^^^^^^^^^^^^^^
  File "/opt/my-package-env/lib/python3.11/site-packages/mypy/__main__.py", line 15, in console_entry
    main()
  File "mypy/main.py", line 99, in main
  File "mypy/main.py", line 203, in run_build
  File "mypy/main.py", line 1489, in maybe_write_junit_xml
  File "mypy/util.py", line 280, in write_junit_xml
  File "<frozen os>", line 225, in makedirs
FileExistsError: [Errno 17] File exists: '/builds/my-package/reports'
Success: no issues found in 10 source files
Error: Sequence aborted after failed subtask 'lint[0]' 

Your Environment

• Mypy version used: 1.7.0
• Mypy command-line flags: None
• Mypy configuration options from mypy.ini (and other config files):
• Python version used: 3.11.6

[tool.mypy]
junit_xml = "reports/mypy.xml"
plugins = "pydantic.mypy"
strict = true
disallow_subclassing_any = false
disallow_untyped_decorators = false
explicit_package_bases = true
ignore_missing_imports = true
pretty = true
show_column_numbers = true
show_error_codes = true
show_error_context = true
warn_unreachable = true
mypy_path = "src"

[tool.pydantic-mypy]
init_forbid_extra = true
init_typed = true
warn_required_dynamic_aliases = true
warn_untyped_fields = true

[lukin0110]

A possible solution can be to change the following in the function write_junit_xml:

os.makedirs(xml_dirs)

to

os.makedirs(xml_dirs, exist_ok=True)

https://github.com/python/mypy/blame/master/mypy/util.py#L320

[JelleZijlstra]

Your fix makes sense, feel free to submit a PR.

[lukin0110]

Thanks. Will make a PR tomorrow.