Our client side error counting spiked from 3k errors a second to 10k due a regression likely caused by T205128. This broke RelatedArticles for some users.
The problem was likely due to the code in mediawiki.template.hogan loading before mobile.startup (which contained a missing webpack runtime module).
While this problem should not happen again it shed some light on the ResourceLoaderMuHoganModule that lives in RelatedArticles and QuickSurveys as being brittle. In fact, in Minerva desktop this code can lead to both Mustache and Hogan being loaded in the client.
original bug report
Exception in module-execute in module mediawiki.template.muhogan:
load.php?debug=false&lang=en&modules=startup&only=scripts&skin=minerva&target=mobile:2 Error: Unknown compiler hogan
I'm seeing this error when I click Special:Random (and land on a lesser used page)
On refreshing, I do not see the error.
I can only reproduce this error on iOS Safari 12.0 on old pages, which makes me think this is a cache problem.
The error triggers statsv, so I think could be contributing to this nasty spike:
mw.loader.getState('mediawiki.template.hogan') "ready" mw.loader.getState('mediawiki.template.muhogan') "error"
I feel like we should stop using templates in this repo.
- ResourceLoaderMuHoganModule should not rely on the targets system to load either mediawiki.template.mustache or mediawiki.template.hogan.