In poking at the code for supporting wikivoyage, it looks to me that the site_identifiers table is populated incorrectly for non-wikipedias.
For wikipedia sites, it has interwiki keys such as 'en'. For wikivoyage, it is 'enwikivoyage'. These are used to construct interwiki links and 'enwikivoyage:Berlin' is not valid. Thus it's problematic to use the sites code for interwiki links.
Is there a good reason for populating the table in this way?
I think the table should have si_key = 'en' for English Wikivoyage. That means a database rows for enwiki and enwikivoyage would be:
4977 | interwiki | en | 4984 | interwiki | en |
****but**** the table defines a si_type and si_key as a unique key, so this does not work currently.
UNIQUE KEY `site_ids_type` (`si_type`,`si_key`),
Any insights on why things are the way they are?
Cheers, Katie