%app.root/modules/contrib/gutenberg is not a directory.

Was this patch against 2.x-dev or specifically 8.x-2.6? If the latter it might already have been fixed by #3277242: You have requested a non-existent parameter "app.root" → ? (Note that drupal search seems to have a bug where "app.root" returns no results; only "app root" finds this issue and the other two.)

Or more likely, has the same problem been fixed by 🐛 Drupal\Core\File\Exception\NotRegularDirectoryException: %app.root/modules/contrib/gutenberg is not a directory Fixed ?

This patch was against 8.x-2.6 and the fix was released in 8.x-2.8 so I'll close this issue.

Issue 🐛 Drupal\Core\File\Exception\NotRegularDirectoryException: %app.root/modules/contrib/gutenberg is not a directory Fixed is indeed where it was fixed.

Automatically closed - issue fixed for 2 weeks with no activity.