Is this a upstream regression?

In T215085#4922102, @Peachey88 wrote:

Is this a upstream regression?

I'm not entirely sure, it needs more investigation.

@Legoktm what was the example that didn't work for you which we were investigating at all-hands?

It still works for some specific examples, like Wikimedia-production-error matches ( logspam )

In T215085#4949680, @mmodell wrote:

@Legoktm what was the example that didn't work for you which we were investigating at all-hands?

It was API not finding MediaWiki-Action-API, despite there being an #api hashtag (ApiFeatureUsage would come first).

This one must really be some edge case. The algorithm seems to be heavily biased towards prefix matching which is probably correct in most cases but it doesn't seem to account for alternate hashtags as much as it should (if at all)

Also see T222870 when it comes to project search results missing items.