[md_inline_extension] Broken with Markdown >= 3.4

Markdown 3.2 deprecated markdown.util.etree, which md_inline_extension currently uses. Markdown 3.4 removed the deprecated etree symbol, which causes md_inline_extension plugin to fail to load with this error message:

Markdown is not installed - inline Markdown extension disabled

Updating the import is not enough to get md_inline_extension working again, after that it fails with:

PelicanInlineMarkdownExtension.extendMarkdown() missing 1 required positional argument: 'md_globals'

Removing md_globals parameter from PelicanInlineMarkdownExtension.extendMarkdown takes us to yet another error:

'Registry' object has no attribute 'add'

Which is caused by this line in pelican_inline_markdown_extension.py. Updating it from .add to .register takes us to the following error (taken with DEBUG=1 for useful stacktraces):

'<' not supported between instances of 'str' and 'int'                                                                                                                                                                                                                                                                            
Traceback (most recent call last):                                                                                                                                                                                                                                                                                                
  File "/home/fidel/Code/blog.fidelramos.net/virtualenv/lib/python3.10/site-packages/pelican/generators.py", line 740, in generate_context                                                                                                                                                                                        
    page = self.readers.read_file(                                                                                                                                                                                                                                                                                                
  File "/home/fidel/Code/blog.fidelramos.net/virtualenv/lib/python3.10/site-packages/pelican/readers.py", line 580, in read_file                                                                                                                                                                                                  
    content, reader_metadata = reader.read(path)                                                                                                                                                                                                                                                                                  
  File "/home/fidel/Code/blog.fidelramos.net/virtualenv/lib/python3.10/site-packages/pelican/readers.py", line 342, in read                                                                                                                                                                                                       
    self._md = Markdown(**self.settings['MARKDOWN'])                                                                                                                                                                                                                                                                              
  File "/home/fidel/Code/blog.fidelramos.net/virtualenv/lib/python3.10/site-packages/markdown/core.py", line 96, in __init__                                                                                                                                                                                                      
    self.registerExtensions(extensions=kwargs.get('extensions', []),                                                                                                                                                                                                                                                              
  File "/home/fidel/Code/blog.fidelramos.net/virtualenv/lib/python3.10/site-packages/markdown/core.py", line 125, in registerExtensions                                                                                                                                                                                           
    ext.extendMarkdown(self)                                                                                                                                                                                                                                                                                                      
  File "/home/fidel/Code/blog.fidelramos.net/virtualenv/lib/python3.10/site-packages/markdown/extensions/footnotes.py", line 82, in extendMarkdown                                                                                                                                                                                
    md.inlinePatterns.register(FootnoteInlineProcessor(FOOTNOTE_RE, self), 'footnote', 175)                                                                                                                                                                                                                                       
  File "/home/fidel/Code/blog.fidelramos.net/virtualenv/lib/python3.10/site-packages/markdown/util.py", line 331, in register                                                                                                                                                                                                     
    self.deregister(name)                                                                                                                                                                                                                                                                                                         
  File "/home/fidel/Code/blog.fidelramos.net/virtualenv/lib/python3.10/site-packages/markdown/util.py", line 343, in deregister                                                                                                                                                                                                   
    index = self.get_index_for_name(name)                                                                                                                                                                                                                                                                                         
  File "/home/fidel/Code/blog.fidelramos.net/virtualenv/lib/python3.10/site-packages/markdown/util.py", line 307, in get_index_for_name                                                                                                                                                                                           
    self._sort()                                                                                                                                                                                                                                                                                                                  
  File "/home/fidel/Code/blog.fidelramos.net/virtualenv/lib/python3.10/site-packages/markdown/util.py", line 357, in _sort                                                                                                                                                                                                        
    self._priority.sort(key=lambda item: item.priority, reverse=True)                                                                                                                                                                                                                                                             
TypeError: '<' not supported between instances of 'str' and 'int'

Which boils down to register() taking an integer as priority and not a string as Registry.add (now deprecated) did.

Hopeful that this was the last error I try again, but alas another error:

'str' object has no attribute 'ANCESTOR_EXCLUDES'                                                                                                                                                                                                                                                                                 
Traceback (most recent call last):                                                                                                                                                                                                                                                                                                
  File "/home/fidel/Code/blog.fidelramos.net/virtualenv/lib/python3.10/site-packages/pelican/generators.py", line 740, in generate_context                                                                                                                                                                                        
    page = self.readers.read_file(                                                                                                                                                                                                                                                                                                
  File "/home/fidel/Code/blog.fidelramos.net/virtualenv/lib/python3.10/site-packages/pelican/readers.py", line 580, in read_file                                                                                                                                                                                                  
    content, reader_metadata = reader.read(path)                                                                                                                                                                                                                                                                                  
  File "/home/fidel/Code/blog.fidelramos.net/virtualenv/lib/python3.10/site-packages/pelican/readers.py", line 344, in read                                                                                                                                                                                                       
    content = self._md.convert(text)                                                                                                                                                                                                                                                                                              
  File "/home/fidel/Code/blog.fidelramos.net/virtualenv/lib/python3.10/site-packages/markdown/core.py", line 268, in convert                                                                                                                                                                                                      
    newRoot = treeprocessor.run(root)                                                                                                                                                                                                                                                                                             
  File "/home/fidel/Code/blog.fidelramos.net/virtualenv/lib/python3.10/site-packages/markdown/treeprocessors.py", line 367, in run                                                                                                                                                                                                
    self.__handleInline(text), child                                                                                                                                                                                                                                                                                              
  File "/home/fidel/Code/blog.fidelramos.net/virtualenv/lib/python3.10/site-packages/markdown/treeprocessors.py", line 127, in __handleInline                                                                                                                                                                                     
    data, matched, startIndex = self.__applyPattern(                                                                                                                                                                                                                                                                              
  File "/home/fidel/Code/blog.fidelramos.net/virtualenv/lib/python3.10/site-packages/markdown/treeprocessors.py", line 258, in __applyPattern                                                                                                                                                                                     
    for exclude in pattern.ANCESTOR_EXCLUDES:                                                                                                                                                                                                                                                                                     
AttributeError: 'str' object has no attribute 'ANCESTOR_EXCLUDES'

At this point I gave up, I will leave a PR in case someone wants to continue, but clearly the Markdown project doesn't care much about backwards-compatibility. :(

getpelican / pelican-plugins

[md_inline_extension] Broken with Markdown >= 3.4 #1373