Trying to mark https://meta.wikimedia.org/wiki/Learning_and_Evaluation/Archive/About_portal for translation via https://meta.wikimedia.org/w/index.php?title=Special:PageTranslation&target=Learning+and+Evaluation%2FArchive%2FAbout+portal&do=mark and I get this:
[WYVHWgpAMEoAALD5yGsAAAAE] 2017-08-05 04:19:38: Fatal exception of type TPException
Applicable permalink: https://meta.wikimedia.org/w/index.php?title=Learning_and_Evaluation/Archive/About_portal&oldid=17075182
Here's the full error message from the Logstash index:
[WYVHWgpAMEoAALD5yGsAAAAE] /w/index.php?title=**&target=**&do=mark TPException from line 314 of /srv/mediawiki/php-1.30.0-wmf.12/extensions/Translate/tag/TranslatablePage.php: Nested <translate> translation units are not allowed. Tag text: <pre> == Further reading == ... * ''[<tvar|<translate> == Overview == </pre>
#0 /srv/mediawiki/php-1.30.0-wmf.12/extensions/Translate/tag/SpecialPageTranslation.php(583): TranslatablePage->getParse()
#1 /srv/mediawiki/php-1.30.0-wmf.12/extensions/Translate/tag/SpecialPageTranslation.php(217): SpecialPageTranslation->checkInput(TranslatablePage, boolean)
#2 /srv/mediawiki/php-1.30.0-wmf.12/extensions/Translate/tag/SpecialPageTranslation.php(75): SpecialPageTranslation->onActionMark(Title, integer)
#3 /srv/mediawiki/php-1.30.0-wmf.12/includes/specialpage/SpecialPage.php(522): SpecialPageTranslation->execute(NULL)
#4 /srv/mediawiki/php-1.30.0-wmf.12/includes/specialpage/SpecialPageFactory.php(578): SpecialPage->run(NULL)
#5 /srv/mediawiki/php-1.30.0-wmf.12/includes/MediaWiki.php(287): SpecialPageFactory::executePath(Title, RequestContext)
#6 /srv/mediawiki/php-1.30.0-wmf.12/includes/MediaWiki.php(868): MediaWiki->performRequest()
#7 /srv/mediawiki/php-1.30.0-wmf.12/includes/MediaWiki.php(523): MediaWiki->main()
#8 /srv/mediawiki/php-1.30.0-wmf.12/index.php(43): MediaWiki->run()
#9 /srv/mediawiki/w/index.php(3): include(string)
#10 {main}So the page on meta needs fixing... And this really needs better handling in Translate
Generally, when you try to save a page with nested translate tags, the fail saves and it tells you not to do that. However, if you subst a template with translate tags, and have that template substitution take place between another set of translate tags, somehow this check is bypassed and the page save happens, but nested translate tags are nonetheless not allowed, so it triggers this exception. So we just need to add another check for nested translate tags.
It's possible to catch the exception when marking page for translation. But how would I detected the nested tags before the page is saved?
This open issue about a PHP error in production did not have a team attached yet. I've tagged it based on Maintainers. Feel free to forward elsewhere if needed.
Closing for now as there are zero occurrences of this in the last 30 days in Logstash, and I also could not reproduce it myself on mediawiki.org.