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Maniphest T264241

Class 'LathMathML' not found
Closed, DuplicatePublicPRODUCTION ERROR
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Description

Error

MediaWiki version: 1.36.0-wmf.11

message
Class 'LathMathML' not found

Impact

train blocker, large volume of errors in production

Notes

Details

Request ID
920b444c-ae68-4573-a4cf-61cd5572479c
Request URL
https://commons.wikimedia.org/w/api.php
Stack Trace
exception.trace
#0 /srv/mediawiki/php-1.36.0-wmf.11/includes/HookContainer/HookContainer.php(333): MathHooks::onParserAfterTidy(Parser, string)
#1 /srv/mediawiki/php-1.36.0-wmf.11/includes/HookContainer/HookContainer.php(140): MediaWiki\HookContainer\HookContainer->callLegacyHook(string, array, array, array)
#2 /srv/mediawiki/php-1.36.0-wmf.11/includes/HookContainer/HookRunner.php(2879): MediaWiki\HookContainer\HookContainer->run(string, array)
#3 /srv/mediawiki/php-1.36.0-wmf.11/includes/parser/Parser.php(1680): MediaWiki\HookContainer\HookRunner->onParserAfterTidy(Parser, string)
#4 /srv/mediawiki/php-1.36.0-wmf.11/includes/parser/Parser.php(649): Parser->internalParseHalfParsed(string, boolean, boolean)
#5 /srv/mediawiki/php-1.36.0-wmf.11/includes/content/WikitextContent.php(374): Parser->parse(string, Title, ParserOptions, boolean, boolean, integer)
#6 /srv/mediawiki/php-1.36.0-wmf.11/includes/content/AbstractContent.php(590): WikitextContent->fillParserOutput(Title, integer, ParserOptions, boolean, ParserOutput)
#7 /srv/mediawiki/php-1.36.0-wmf.11/includes/Revision/RenderedRevision.php(266): AbstractContent->getParserOutput(Title, integer, ParserOptions, boolean)
#8 /srv/mediawiki/php-1.36.0-wmf.11/includes/Revision/RenderedRevision.php(235): MediaWiki\Revision\RenderedRevision->getSlotParserOutputUncached(WikitextContent, boolean)
#9 /srv/mediawiki/php-1.36.0-wmf.11/includes/Revision/RevisionRenderer.php(230): MediaWiki\Revision\RenderedRevision->getSlotParserOutput(string, array)
#10 /srv/mediawiki/php-1.36.0-wmf.11/includes/Revision/RevisionRenderer.php(152): MediaWiki\Revision\RevisionRenderer->combineSlotOutput(MediaWiki\Revision\RenderedRevision, array)
#11 [internal function]: MediaWiki\Revision\RevisionRenderer->MediaWiki\Revision\{closure}(MediaWiki\Revision\RenderedRevision, array)
#12 /srv/mediawiki/php-1.36.0-wmf.11/includes/Revision/RenderedRevision.php(197): call_user_func(Closure, MediaWiki\Revision\RenderedRevision, array)
#13 /srv/mediawiki/php-1.36.0-wmf.11/includes/poolcounter/PoolWorkArticleView.php(216): MediaWiki\Revision\RenderedRevision->getRevisionParserOutput()
#14 /srv/mediawiki/php-1.36.0-wmf.11/includes/poolcounter/PoolCounterWork.php(162): PoolWorkArticleView->doWork()
#15 /srv/mediawiki/php-1.36.0-wmf.11/includes/page/WikiPage.php(1221): PoolCounterWork->execute()
#16 /srv/mediawiki/php-1.36.0-wmf.11/includes/api/ApiParse.php(83): WikiPage->getParserOutput(ParserOptions, integer, boolean)
#17 /srv/mediawiki/php-1.36.0-wmf.11/includes/poolcounter/PoolCounterWorkViaCallback.php(74): ApiParse->{closure}()
#18 /srv/mediawiki/php-1.36.0-wmf.11/includes/poolcounter/PoolCounterWork.php(162): PoolCounterWorkViaCallback->doWork()
#19 /srv/mediawiki/php-1.36.0-wmf.11/includes/api/ApiParse.php(90): PoolCounterWork->execute()
#20 /srv/mediawiki/php-1.36.0-wmf.11/includes/api/ApiParse.php(658): ApiParse->getPageParserOutput(WikiFilePage, NULL, ParserOptions, boolean)
#21 /srv/mediawiki/php-1.36.0-wmf.11/includes/api/ApiParse.php(222): ApiParse->getParsedContent(WikiFilePage, ParserOptions, boolean, NULL, NULL, boolean)
#22 /srv/mediawiki/php-1.36.0-wmf.11/includes/api/ApiMain.php(1565): ApiParse->execute()
#23 /srv/mediawiki/php-1.36.0-wmf.11/includes/api/ApiMain.php(545): ApiMain->executeAction()
#24 /srv/mediawiki/php-1.36.0-wmf.11/includes/api/ApiMain.php(516): ApiMain->executeActionWithErrorHandling()
#25 /srv/mediawiki/php-1.36.0-wmf.11/api.php(90): ApiMain->execute()
#26 /srv/mediawiki/php-1.36.0-wmf.11/api.php(45): wfApiMain()
#27 /srv/mediawiki/w/api.php(3): require(string)
#28 {main}

Related Objects
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StatusSubtypeAssignedTask
 ResolvedReleasedduvallT263177 1.36.0-wmf.11 deployment blockers
 DuplicatePRODUCTION ERRORNoneT264241 Class 'LathMathML' not found

Event Timeline

• mmodell created this task.Sep 30 2020, 9:02 PM
Restricted Application added a subscriber: Aklapper. · View Herald TranscriptSep 30 2020, 9:02 PM
• mmodell triaged this task as Unbreak Now! priority.Sep 30 2020, 9:09 PM
• mmodell added a parent task: T263177: 1.36.0-wmf.11 deployment blockers.
cscott subscribed.Sep 30 2020, 9:14 PM

Hm, strange, codesearch doesn't know anything about LathMathML...
https://codesearch.wmcloud.org/search/?q=LathMathML&i=nope&files=&repos=
Must be a constructed class name somehow?

cscott added a comment.Sep 30 2020, 9:15 PM

This is a bug in the Math extension's ParserAfterTidy hook:

#0 /srv/mediawiki/php-1.36.0-wmf.11/includes/HookContainer/HookContainer.php(333): MathHooks::onParserAfterTidy(Parser, string)
cscott added a subscriber: DannyS712.EditedSep 30 2020, 9:16 PM

Maybe 3f16b9f1c2af13dfc4e9758e17fa9d086f9c35a4 or caa51dc4c9bd2b3dcbc7516d5f24d7531b37f1f1 (@DannyS712 )? Those were the most recent changes to MathHooks, and both took place since wmf.10....

DannyS712 added a comment.Sep 30 2020, 9:17 PM
In T264241#6506938, @cscott wrote:

Hm, strange, codesearch doesn't know anything about LathMathML...
https://codesearch.wmcloud.org/search/?q=LathMathML&i=nope&files=&repos=
Must be a constructed class name somehow?

Not only that, but it doesn't look like anything with the extension has changed that would cause this

rEMATcaa51dc4c9bd: Remove fallback to $wgUser in MathHooks::onPageRenderingHash - my commit
rEMATdb617781c137: build: Updating mediawiki/mediawiki-phan-config to 0.10.3 - bot commit
rEMAT3f16b9f1c2af: Remove use of $wgUser in onMaintenanceRefreshLinksInit - my commit
rEMAT18b8b1f29e03: Localisation updates from https://translatewiki.net. - bot commit

I double checked my patches, but they didn't touch anything like this

cscott added a comment.Sep 30 2020, 9:20 PM

This might be a corruption bug. There's a call to MathMathML::batchEvaluate on line 352 of MathHooks::onParserAfterTidy. Seems like PHP is corrupting its strings somehow to turn MathMathML into LathMathML, and then crashing?

ssastry subscribed.Sep 30 2020, 9:24 PM

One of the log traces is https://logstash.wikimedia.org/app/kibana#/doc/logstash-*/logstash-deploy-2020.09.30/mediawiki?id=AXTg4LY_LNRtRo5XnEue&_g=h@44136fa which is line 356 of wmf-10.

Line number 356 of /srv/mediawiki/php-1.36.0-wmf.10/extensions/Math/src/MathHooks.php:356 is MathMathML::batchEvaluate( self::$tags );

cscott added a comment.EditedSep 30 2020, 9:26 PM

@ssastry noticed that the crash is reported on line 356. That's the line with MathMathML::batchEvaluate *in wmf.10*. @DannyS712's patches changed the line numbers just enough so that the line with MathMathML::batchEvaluate is now line 352.

So this is definitely pointing to some deployment issue: we're crashing on a line which *in wmf.10* contained a MathMathML which "at the time of the crash" seems to contain LathMathML but which *in wmf.11 is a comment*.

ssastry added a comment.Sep 30 2020, 9:26 PM

So, that does lend credence to @cscott's theory of some corruption here during deploy. Are the PHP bytecode caches cleared out properly?

• mmodell added a comment.Sep 30 2020, 9:29 PM

It does seem like something was massively wrong because the number of crazy and unrelated errors were off the chart, and the error rate didn't return to normal until I rolled back even group0 to wmf.10

Multichill subscribed.Sep 30 2020, 9:40 PM

I had about 20 bots running and all crashed with errors like:

ERROR: Detected MediaWiki API exception internal_api_error_Error: [ba1d3188-6194-41dc-8306-24e1f42c3c02] Caught exception of type Error

In logstash I found : [ba1d3188-6194-41dc-8306-24e1f42c3c02] /w/api.php Error from line 356 of /srv/mediawiki/php-1.36.0-wmf.10/extensions/Math/src/MathHooks.php: Class 'LathMathML' not found

Search also returns some Wikibase errors that don't seem to be related?

ssastry edited projects, added serviceops; removed Parsing-Team--ARCHIVED, MediaWiki-Parser.Sep 30 2020, 10:05 PM

I'm going to untag the parsing-team and parser since I don't think this is related to both of those tags. Tagging serviceops in case they have insight into this.

CDanis closed this task as a duplicate of T245183: PHP7 corruption reports in 2020-2022 (Call on wrong object, etc.).EditedSep 30 2020, 10:06 PM
CDanis subscribed.

This is opcache corruption.

It occurred on just a small number of machines, and restarting php-fpm on them cleared it.

Lucas_Werkmeister_WMDE mentioned this in T264243: Argument 2 passed to Wikibase\Repo\Store\TypeDispatchingEntityTitleStoreLookup::__construct() must be an instance of Wikibase\Repo\Store\EntityTitleStoreLookup, instance of Wikibase\Repo\Content\EntityContentFactory given.Oct 1 2020, 10:54 AM
ssastry mentioned this in T245183: PHP7 corruption reports in 2020-2022 (Call on wrong object, etc.).Oct 1 2020, 4:52 PM
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