ERROR - unexpected error: SuperFencesCodeExtension.extend_super_fences() missing 1 required positional argument: 'reset #76

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1. johnpiers commented on Sep 25, 2026

   

   johnpiers

   on Sep 25, 2026

   Last edited by johnpiers

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   Root cause, more precisely: pymdown-extensions 12.1 changed SuperFencesCodeExtension.extend_super_fences() to require a 4th positional argument, reset (a callback for clearing any state a custom fence type holds between renders — 12.1 defaults to a no-op, default_reset, for its own built-in custom fences when nothing else is given). extension.py here only ever calls it with 3 arguments, which is what throws on 12.1+.

   A version-tolerant fix, tested against both 12.0.1 and 12.1:

   try:
       from pymdownx.superfences import default_validator, fence_code_format, _formatter, _validator
       try:
           # pymdown-extensions 12.1+ requires a 4th 'reset' argument
           from pymdownx.superfences import _reset, default_reset
           extension.extend_super_fences(
               "markmap",
               partial(_formatter, class_name="language-markmap", _fmt=fence_code_format),
               partial(_validator, validator=default_validator),
               partial(_reset, _reset=default_reset)
           )
       except ImportError:
           # pymdown-extensions < 12.1 has no 'reset' argument
           extension.extend_super_fences(
               "markmap",
               partial(_formatter, class_name="language-markmap", _fmt=fence_code_format),
               partial(_validator, validator=default_validator)
           )
       break
   
   except ImportError as e:
       log.warning(f"markmap detected pymdownx.superfences, but import is not working: {e}")

   This works on both 12.0.1 and 12.1+, so no pinning is needed once it's in.
   Happy to open a PR if that's useful.