Right now, the migration code takes a language code. It's use-case is to get the plural rule categories from cldr, which are defined for some combination of language and region tags. We should make the conversion between the locale code we have and what cldr knows about inside cldr.py. We should fix that before we land the migration mach command in bug 1315005.
Do you think we should run some kind of a language negotiation here, or just hard-code the mapping from codes used at Mozilla to codes known by CLDR?
I'd fallback in the sense of ja-JP-mac -> ja-JP -> ja. Nothing fancier than that. I think that's easier than hard-coding 20+ entries.
Created attachment 8814464 [details] [review] Pull request
Comment on attachment 8814464 [details] [review] Pull request r=me