So far, the only wikis where we’ve found <translate>-powered interface messages are Wikidata and Test Wikidata (example there). Maybe we can roll back the train only for those two wikis? (The issue seems to be new in wmf.6, e.g. it didn’t happen two days ago.)

Edit: Or only roll back wikidatawiki and leave testwikidatawiki broken, so it’s easier to test a fix there.

Possibly caused due to changes made for T302754: Fatal exception of type "BadMethodCallException" on MediaWiki.org Special:RecentChanges filter widget

Related patch: 774899: PageTranslationHooks: Don't kick in during interface message parsing | https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Translate/+/774899

Change 777762 had a related patch set uploaded (by Abijeet Patro; author: Abijeet Patro):

[mediawiki/extensions/Translate@master] Do not skip parsing of interface messages

https://gerrit.wikimedia.org/r/777762

I was under the impression that nobody uses <translate> tags in the MediaWiki namespace. However, search says that I am wrong: https://global-search.toolforge.org/?q=%5C%3Ctranslate%5C%3E&regex=1&namespaces=8&title=

I do not consider this a supported use case. I think these should be migrated to other solutions (which have known issues, but we can look into fixing those). For short term, the revert is the best option.

Change 777767 had a related patch set uploaded (by Nikerabbit; author: Abijeet Patro):

[mediawiki/extensions/Translate@wmf/1.39.0-wmf.6] Revert "PageTranslationHooks: Don't kick in during interface message parsing"

https://gerrit.wikimedia.org/r/777767

Change 777767 merged by jenkins-bot:

[mediawiki/extensions/Translate@wmf/1.39.0-wmf.6] Revert "PageTranslationHooks: Don't kick in during interface message parsing"

https://gerrit.wikimedia.org/r/777767

Mentioned in SAL (#wikimedia-operations) [2022-04-06T13:29:24Z] <kartik@deploy1002> Synchronized php-1.39.0-wmf.6/extensions/Translate/tag/PageTranslationHooks.php: Backport: [[gerrit:777767|Revert "PageTranslationHooks: Don't kick in during interface message parsing" (T305531)]] (duration: 00m 57s)

Removing from train blocker since the faulty patch got reverted but I made it a blocker for next week train (T305213)

In T305531#7834854, @Nikerabbit wrote:

I was under the impression that nobody uses <translate> tags in the MediaWiki namespace. However, search says that I am wrong: https://global-search.toolforge.org/?q=%5C%3Ctranslate%5C%3E&regex=1&namespaces=8&title=

I do not consider this a supported use case. I think these should be migrated to other solutions (which have known issues, but we can look into fixing those). For short term, the revert is the best option.

The noinclude tag is not supported during message parsing, somehow <languages/> tag does not appear in the result and people may think that's a valid use case...

I'm removing this task as a train blocker for wmf.7.

Change 777762 merged by jenkins-bot:

[mediawiki/extensions/Translate@master] PageTranslationHooks: Skip display title & section preview processing

https://gerrit.wikimedia.org/r/777762