Critical CSS module prevents from using the admin theme

I can't tell why, but the simple injection of the Twig service (TwigEnvironment) seems to be the enough to cause the problem.

It is not tied to any particular use of that service. You can delete all uses of $twig inside the decorated service and it will fail the same.

To reproduce, just delete the Twig injected service:

critical_css/critical_css.services.yml

services:
  asset.css.collection_renderer.critical_css:
    public: false
    class: Drupal\critical_css\Asset\CssCollectionRenderer
    decorates: asset.css.collection_renderer
    arguments:
      - '@asset.css.collection_renderer.critical_css.inner'
      - '@config.factory'
      - '@twig' <-----------------REMOVE THIS
      - '@critical_css'

...and also from critical_css/src/Asset/CssCollectionRenderer.php.

Then, it will work as usual.

WORKAROUND! This is NOT a fix for the issue
WORKAROUND! This is NOT a fix for the issue
WORKAROUND! This is NOT a fix for the issue

The attached patch removes the twig injected service (and, of course, the debug functionality of the module).

This will make the bug disappear but can't be considered a solution to the issue, just a workaround.

Hi,

I cannot reproduce this issue, could you please try it again and provide more details?

Thanks

Dealing with the same issue here, the work around of idiaz.roncero works, but waiting for a better solution here :)

This problem is caused by 🐛 Enabling SDC causes the frontend theme to be used in admin routes Needs work and can be fixed by patching Drupal core with the MR from that issue. This issue only occurs when the SDC module is installed, that's why not everyone seems to be able to reproduce it.

Can replicate this on 10.2.4, with SDC enabled. The patch from this MR fixes the problem.

+1 to this issue.