Issue with parsing comments in flake8 config

[vinitkumar]

how did you install flake8?

pip install --upgrade flake8



Requirement already satisfied: flake8 in ./venv/lib/python3.10/site-packages (5.0.4)
Collecting flake8
  Downloading flake8-6.0.0-py2.py3-none-any.whl (57 kB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 57.8/57.8 kB 2.4 MB/s eta 0:00:00
Requirement already satisfied: flake8-bugbear in ./venv/lib/python3.10/site-packages (22.10.27)

### unmodified output of `flake8 --bug-report`

```json
{
  "platform": {
    "python_implementation": "CPython",
    "python_version": "3.10.2",
    "system": "Darwin"
  },
  "plugins": [
    {
      "plugin": "flake8-bugbear",
      "version": "22.10.27"
    },
    {
      "plugin": "mccabe",
      "version": "0.7.0"
    },
    {
      "plugin": "pycodestyle",
      "version": "2.10.0"
    },
    {
      "plugin": "pyflakes",
      "version": "3.0.0"
    }
  ],
  "version": "6.0.0"
}

describe the problem

what I expected to happen

diff --git a/setup.cfg b/setup.cfg
index 5948cc21..3cc6eeea 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -25,11 +25,11 @@ ignore =
     W504,
     F403,
     B007,
-    F401, # ignore unused imports for now and fix the real issues
+    F401,
     B950,
-    W605, # regex related warnings
+    W605,
     W503,
-    N806, # variable naming in django inside function might not be lowercase, since we can also use class name import
+    N806,

My flake8 config in setup.cfg had comments to explain some of the rules. They worked in all previous version of flake8. However, with this latest version, I had to comment this out for flake8 to work, or I will just get a crash like this:

Traceback (most recent call last):
  File "/Users/vinitkumar/projects/python/socialschools-intranet/venv/bin/flake8", line 8, in <module>
    sys.exit(main())
  File "/Users/vinitkumar/projects/python/socialschools-intranet/venv/lib/python3.10/site-packages/flake8/main/cli.py", line 23, in main
    app.run(argv)
  File "/Users/vinitkumar/projects/python/socialschools-intranet/venv/lib/python3.10/site-packages/flake8/main/application.py", line 198, in run
    self._run(argv)
  File "/Users/vinitkumar/projects/python/socialschools-intranet/venv/lib/python3.10/site-packages/flake8/main/application.py", line 186, in _run
    self.initialize(argv)
  File "/Users/vinitkumar/projects/python/socialschools-intranet/venv/lib/python3.10/site-packages/flake8/main/application.py", line 165, in initialize
    self.plugins, self.options = parse_args(argv)
  File "/Users/vinitkumar/projects/python/socialschools-intranet/venv/lib/python3.10/site-packages/flake8/options/parse_args.py", line 53, in parse_args
    opts = aggregator.aggregate_options(option_manager, cfg, cfg_dir, rest)
  File "/Users/vinitkumar/projects/python/socialschools-intranet/venv/lib/python3.10/site-packages/flake8/options/aggregator.py", line 30, in aggregate_options
    parsed_config = config.parse_config(manager, cfg, cfg_dir)
  File "/Users/vinitkumar/projects/python/socialschools-intranet/venv/lib/python3.10/site-packages/flake8/options/config.py", line 131, in parse_config
    raise ValueError(
ValueError: Error code '#' supplied to 'ignore' option does not match '^[A-Z]{1,3}[0-9]{0,3}$'

It looks like the support for comments in flake8 config is deprecated, or maybe it is a regression.

[asottile]

please search the issue tracker next time #1750 -- or read the changelog or the flake8 configuration docs