Loading plugin from module broken in v4.5.1

[clokep]

• I have read the Filing Issues and subsequent “How to Get Help” sections of the documentation.

• I have searched the issues (including closed ones) and believe that this is not a duplicate.

• OS version and name: macOS 11.2.3

• Python version: 3.7.7

• Pelican version: 4.5.1

• Link to theme: N/A

• Links to plugins: assets, extract_toc, gravatar, pelican_youtube.youtube, share_post, thumbnailer

• Link to your site: https://patrick.cloke.us

• Link to your source: https://github.com/clokep/clokep.github.io @ eba8c9588b5d4f136d0cb73db7fe1752bcbc6055

• Link to a Gist with the contents of your settings file: See above

Issue

Building of my site broke when upgrading from Pelican 4.5.0 to 4.5.1 (sorry this took so long to file, was trying to track down why). I tracked this down to #2813, reverting 991c00a fixes the issue for me.

The error is:

ERROR: Cannot load plugin `pelican_youtube.youtube`
  | Cannot import plugin `pelican_youtube.youtube`
ERROR: Could not process articles/matrix-live-interview.rst
  | /Users/clokep/code/blog/blog/content/articles/matrix-live-interview.rst:20: (ERROR/3) Unknown directive type "youtube".

.. youtube:: iKx-RHS-p4M
    :nocookie: yes

The first error is the interesting one (since the second is a direct result of it).

Note that I'm not loading this plug-in from a plugin-path, but it is installed as a package (from PyPI).

I did find a workaround, which was to import the module and pass it directly to plugins instead of passing it as a string:

from youtube_pelican import youtube

PLUGINS = [
    ...,
    youtube,
]

I figured I'd file this anyway since it isn't clear to me if what I was doing before is supposed to work or not.

Thanks for your help! (And thanks for working Pelican! 😄 )

[clokep]

I should note that Pelican 4.5.1+ has the same behavior (I've tested on 4.5.4 and 4.6.0).

[avaris]

Interesting. I think this is triggered because there is pelican_youtube inside pelican-plugins but it is not importable. It's in its package/installable form. So it takes precedence and marked as "found" but actual import fails. I'm guessing any one of these would "fix" this:

• Remove/rename pelican_youtube inside pelican-plugins of your local copy
• Prepend pelican-plugins/pelican_youtube in PLUGIN_PATHS:

PLUGIN_PATHS = [
    'pelican-plugins/pelican_youtube',
    'pelican-plugins'
]

First, it doesn't make much sense to put pelican_youtube in pelican-plugins like that, since that repository supposed to contain submodules/folders that are importable. Having said that, importer in pelican should be a bit more lenient and be able to resolve this. So I'd still consider this as a bug. Thanks for reporting.

[clokep]

Ah, interesting. That does seem to be the issue. Setting PLUGIN_PATHS = [] works! 🎉 (Of course it means I can't use any other plug-ins except for pelican_youtube.youtube` though.)

Your workaround of removing it from my local copy of pelican-plugins also works.

Thanks so much for taking the time to investigate! I think this is also essentially fixed by the new-style plugins. 👍