mkdocs python parser is failing when building the pages

[Monallabs]

Details

• Read the Docs project URL: https://readthedocs.org/projects/addict-tracking-changes/
• Build URL (if applicable): https://readthedocs.org/projects/{your_project_slug}/builds/{build_id}/
• Read the Docs username (if applicable): https://readthedocs.org/profiles/Kabira/

Expected Result

I am not sure if I am doing the steps correctly. I wrote some docs in markdown under docs/ folder
of my github project. Then used mkdocs build and mkdocs gh-deploy to push to github under gh-pages branch.

On readthedocs, after registering the project, and selected documentation type as mkdocs. The build starts
but crashes.

A description of what you wanted to happen
I hoped to build process to report invalid format or the build to complete

Actual Result

An error due to jinja2 parsing.

The actual output:

Traceback (most recent call last):
  File "/home/docs/.pyenv/versions/3.7.9/lib/python3.7/runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "/home/docs/.pyenv/versions/3.7.9/lib/python3.7/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/home/docs/checkouts/readthedocs.org/user_builds/addict-tracking-changes/envs/latest/lib/python3.7/site-packages/mkdocs/__main__.py", line 14, in <module>
    from mkdocs import config
  File "/home/docs/checkouts/readthedocs.org/user_builds/addict-tracking-changes/envs/latest/lib/python3.7/site-packages/mkdocs/config/__init__.py", line 2, in <module>
    from mkdocs.config.defaults import DEFAULT_SCHEMA
  File "/home/docs/checkouts/readthedocs.org/user_builds/addict-tracking-changes/envs/latest/lib/python3.7/site-packages/mkdocs/config/defaults.py", line 4, in <module>
    from mkdocs.config import config_options
  File "/home/docs/checkouts/readthedocs.org/user_builds/addict-tracking-changes/envs/latest/lib/python3.7/site-packages/mkdocs/config/config_options.py", line 8, in <module>
    from mkdocs import utils, theme, plugins
  File "/home/docs/checkouts/readthedocs.org/user_builds/addict-tracking-changes/envs/latest/lib/python3.7/site-packages/mkdocs/theme.py", line 9, in <module>
    from mkdocs.utils import filters
  File "/home/docs/checkouts/readthedocs.org/user_builds/addict-tracking-changes/envs/latest/lib/python3.7/site-packages/mkdocs/utils/filters.py", line 11, in <module>
    @jinja2.contextfilter
AttributeError: module 'jinja2' has no attribute 'contextfilter'

A description of what actually happened
The build engine broke.

[humitos]

Hi @Monallabs! Thanks for reporting this issue. It looks duplicated of #9081. Please, use the latest version of MkDocs for building your documentation.