'str' object has no attribute 'supported' when building documentation using m2r2

[brsc2909]

Describe the bug
when i add the m2r2 extension to my project is get the error below

To Reproduce

$ pip install m2r2
$ mkdir testdoc && cd testdoc

Add m2r2 to extensions in conf.py

# Configuration file for the Sphinx documentation builder.
#
# This file only contains a selection of the most common options. For a full
# list see the documentation:
# https://www.sphinx-doc.org/en/master/usage/configuration.html

# -- Path setup --------------------------------------------------------------

# If extensions (or modules to document with autodoc) are in another directory,
# add these directories to sys.path here. If the directory is relative to the
# documentation root, use os.path.abspath to make it absolute, like shown here.
#
# import os
# import sys
# sys.path.insert(0, os.path.abspath('.'))


# -- Project information -----------------------------------------------------

project = 'test'
copyright = '2020, bs'
author = 'bs'


# -- General configuration ---------------------------------------------------

# Add any Sphinx extension module names here, as strings. They can be
# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
# ones.
extensions = ['m2r2']

# Add any paths that contain templates here, relative to this directory.
templates_path = ['_templates']

# List of patterns, relative to source directory, that match files and
# directories to ignore when looking for source files.
# This pattern also affects html_static_path and html_extra_path.
exclude_patterns = ['_build', 'Thumbs.db', '.DS_Store']


# -- Options for HTML output -------------------------------------------------

# The theme to use for HTML and HTML Help pages.  See the documentation for
# a list of builtin themes.
#
html_theme = 'alabaster'

# Add any paths that contain custom static files (such as style sheets) here,
# relative to this directory. They are copied after the builtin static files,
# so a file named "default.css" will overwrite the builtin "default.css".
html_static_path = ['_static']

Make docs

$ make html

Error:

$ make html
Running Sphinx v3.3.0

Exception occurred:
  File "/home/username/PycharmProjects/project/venv/lib/python3.8/site-packages/sphinx/registry.py", line 266, in add_source_parser
    for filetype in parser.supported:
AttributeError: 'str' object has no attribute 'supported'
The full traceback has been saved in /tmp/sphinx-err-bk5vovm_.log, if you want to report the issue to the developers.
Please also report this if it was a user error, so that a better error message can be provided next time.
A bug report can be filed in the tracker at <https://github.com/sphinx-doc/sphinx/issues>. Thanks!
make: *** [Makefile:20: html] Error 2

Expected behavior
A clear and concise description of what you expected to happen.

Environment info

• OS: Linux manjaro 20.1 KDE plasma
• Python version: 3.8.6
• Sphinx version: 3.3.0
• Sphinx extensions: m2r2

[brsc2909]

This can be closed it's fixed in
CrossNox/m2r2@484b792

[cglacet]

I'm still getting this error with the latest version of m2r2 0.2.5 (and sphinx 3.3.0).

[cglacet]

On the other hand the proposed patch does work.

[brsc2909]

I'm still getting this error with the latest version of m2r2 0.2.5 (and sphinx 3.3.0).

The fix hasn't been merged yet, it's still waiting on this pull request CrossNox/m2r2#14.

[cglacet]

"8 days ago" ok. Is there a single person with merge rights on m2r2? It's a bit strange to spend 8 days approving this kind of edit. Anyway, thanks for the issue you saved me quite a bit of time :D

[cglacet]

In the mean time, conf.py:

"""Patching m2r2"""
import m2r2

current_m2r2_setup = m2r2.setup

def patched_m2r2_setup(app):
    try:
        return current_m2r2_setup(app)
    except (AttributeError):
        app.add_source_suffix(".md", "markdown")
        app.add_source_parser(m2r2.M2RParser)
    return dict(
        version=m2r2.__version__, parallel_read_safe=True, parallel_write_safe=True,
    )

m2r2.setup = patched_m2r2_setup

[Sherryzhang2]

I also met this problem. Has this issue been fixed and merged into any release version?

[KaiSchwarz-cnic]

I am also running into this problem. But will try to get the above workaround applied.

[KaiSchwarz-cnic]

fyi I am reading somewhere else about a plugin m2r2 - looks like m2r is abandoned. replacing m2r might fix it.
CrossNox/m2r2#13

I'll give that a try and will post the result. -> Yes, fixed.

[martinm82]

@Papakai using m2r2 fixes indeed the problem. Thanks for the workaround