The build process currently requires the theme to be inside the OOUI repo to work; this needs to be improved.
|Declined||None||T76633 Move the "WikimediaUI" OOjs UI theme to the MediaWiki repo|
|Open||None||T155562 Make it easier to create an OOUI theme|
|Open||Daegontaven||T76632 OOUI themes should be able to be moved out to another repo|
Well it's still just as impossible as before? IIRC James closed this after I did rGOJU09d210d61d8c: Implement `grunt add-theme` task to ease theme creation, but that doesn't resolve this task (it only helps you add themes if you fork OOUI).