Update problem at 0.28.0 -> 0.29.0

[Lasica]

I've found that my spellcheck config works for version 0.28.0 and before, but at 0.29.0 I have the following crash:

Checking files matching specified outlined in >.spellcheck.yml<
----------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/local/bin/pyspelling", line 8, in <module>
    sys.exit(main())
             ^^^^^^
  File "/usr/local/lib/python3.11/site-packages/pyspelling/__main__.py", line 30, in main
    return run(
           ^^^^
  File "/usr/local/lib/python3.11/site-packages/pyspelling/__main__.py", line 55, in run
    for results in spellcheck(
  File "/usr/local/lib/python3.11/site-packages/pyspelling/__init__.py", line 673, in spellcheck
    for result in spellchecker.run_task(task, source_patterns=sources):
  File "/usr/local/lib/python3.11/site-packages/pyspelling/__init__.py", line 311, in run_task
    self._build_pipeline(task)
  File "/usr/local/lib/python3.11/site-packages/pyspelling/__init__.py", line 265, in _build_pipeline
    self.pipeline_steps.append(module(options, **kwargs))
                               ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/pyspelling/filters/context.py", line 17, in __init__
    super().__init__(options, default_encoding)
  File "/usr/local/lib/python3.11/site-packages/pyspelling/filters/__init__.py", line 86, in __init__
    super().__init__(options)
  File "/usr/local/lib/python3.11/site-packages/pyspelling/plugin.py", line 23, in __init__
    self.setup()
  File "/usr/local/lib/python3.11/site-packages/pyspelling/filters/context.py", line 72, in setup
    self.delimiters.append((re.compile(pattern, re.M), group))
                            ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/re/__init__.py", line 227, in compile
    return _compile(pattern, flags)
           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/re/__init__.py", line 294, in _compile
    p = _compiler.compile(pattern, flags)
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/re/_compiler.py", line 743, in compile
    p = _parser.parse(p, flags)
        ^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/re/_parser.py", line 980, in parse
    p = _parse_sub(source, state, flags & SRE_FLAG_VERBOSE, 0)
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/re/_parser.py", line 455, in _parse_sub
    itemsappend(_parse(source, state, verbose, nested + 1,
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/re/_parser.py", line 841, in _parse
    raise source.error('global flags not at the start '
re.error: global flags not at the start of the expression at position 1
::error title=Spelling errors::Files in repository contain spelling errors

and it occurs in all higher versions. Here's my spellcheck.yml:

spellchecker: aspell
matrix:
  - name: Check the english docs
    aspell:
      ignore-case: ""
      lang: en
    sources:
      - "docs/**/*.md"
      - "CONTRIBUTING.md"
      - "README.md"
    default_encoding: utf-8
    pipeline:
    - pyspelling.filters.context:
        context_visible_first: true
        escapes: \\[\\`~]
        delimiters:
          # Ignore multiline content between fences (fences can have 3 or more back ticks)
          # ```
          # content
          # ```
          - open: '^(?s)(?P<open>`{1,3})[^`]'
            close: '(?P=open)'
          # Ignore text between inline back ticks
          - open: '(?P<open>`)[^`]'
            close: '(?P=open)'
          # Ignore text in brackets [] and ()
          - open: '\['
            close: '\]'
          - open: '\('
            close: '\)'
          - open: '\{'
            close: '\}'
    - pyspelling.filters.markdown:
        markdown_extensions:
        - pymdownx.superfences
    dictionary:
      wordlists:
        - docs/spellcheck_exceptions.txt

Any ideas what could be the issue? I've checked changelog to see what's changed in those versions but apart from python/library updates I didn't see anything. There was also addition of markdown check to default spelling.yml

[Lasica]

Ok I see this is regex python 3.11 issue:
https://docs.python.org/3/whatsnew/3.11.html#porting-to-python-3-11

[Lasica]

So we can close it, leave it archived so maybe someone else encounters this issue.

the (?s) in regex was the cause.

[jonasbn]

Created a new diagnostic section in the documentation based on this, ref: #190