The code review for converting Cosmos to be properly namespaced was done as part of T265107. However, there had to be a follow-up patch in https://gerrit.wikimedia.org/r/c/mediawiki/skins/Cosmos/+/633763 as a use statement was accidentally missed. This was missed since I didn't have any of the extensions that Cosmos integrates with installed, and that static call to SpecialPage only gets run when CreateRedirect extension is installed at the same time.
To mitigate this, we should add a patch to integration-config repository to also install the following extensions whenever it runs CI jobs for Cosmos:
- AdminLinks
- CreateRedirect
- DismissableSiteNotice
- Echo
- ManageWiki
- SocialProfile
- VisualEditor