The vagrant default wiki is not in the interwiki table / sites table which means it can not be linked in the wikidata wiki.
|Open||None||T129223 (tracking) Problems with wikidata vagrant role|
|Open||None||T93375 vagrant default wiki is not in interwiki table / sites table which means it can not be linked in wikidata|
This might be a fun hackathon project for someone to work on. We don't have any really great cli tools for managing cdb files (CRUD operations) and the structure of the CDB file for this is un/under documented. If we had a clear description of how to add a site to the cache and a cli tool for querying and manipulating the CDB file it would be relatively easy to wire that into the ::mediawiki::wiki puppet resource.
After some discussion on irc I think that what I was suggesting for this bug may be useful but really won't get the whole job done. Perhaps when T47532: Add file-based cached implementation of SiteStore has been implemented we can actually create the data set that wikidata is wanting reasonably for a dynamic mw-vagrant farm.
After enabling Flow I ended up with a small wiki farm. After enabling role interwiki I could manage interwiki links at the page special:interwiki. That might help in the wikidata role as well.