Page MenuHomePhabricator
Create Task
Maniphest T405901

APCU + languageconverter dynamic property creation error with PHP 8.4
Open, HighPublicBUG REPORT
Actions

Description

Steps to replicate the issue (include links if applicable):

  • MediaWiki 1.43.3, PHP 8.4.11,
$wgMainCacheType = CACHE_ACCEL;
$wgParserCacheType = 'apcu';
$wgMessageCacheType = 'apcu';
$wgSessionsInObjectCache = true;
$wgSessionCacheType = 'apcu';
$wgEnableSidebarCache = true;

What happens?:

Deprecated: Creation of dynamic property MediaWiki\Language\ReplacementArray::$data is deprecated in /srv/wiki.gslin.org/public/includes/libs/objectcache/APCUBagOStuff.php on line 70
[89b7981d01fd3cdada982ae7] /wiki/%E9%A6%96%E9%A1%B5 Error: Typed property MediaWiki\Language\ReplacementArray::$data must not be accessed before initialization

Backtrace:

from /srv/wiki.gslin.org/public/includes/libs/ReplacementArray.php(104)
#0 /srv/wiki.gslin.org/public/includes/language/LanguageConverter.php(623): MediaWiki\Language\ReplacementArray->replace()
#1 /srv/wiki.gslin.org/public/includes/language/LanguageConverter.php(602): MediaWiki\Language\LanguageConverter->translate()
#2 /srv/wiki.gslin.org/public/includes/language/LanguageConverter.php(829): MediaWiki\Language\LanguageConverter->autoConvert()
#3 /srv/wiki.gslin.org/public/includes/language/LanguageConverter.php(584): MediaWiki\Language\LanguageConverter->recursiveConvertTopLevel()
#4 /srv/wiki.gslin.org/public/includes/language/LanguageConverter.php(829): MediaWiki\Language\LanguageConverter->autoConvert()
#5 /srv/wiki.gslin.org/public/includes/language/LanguageConverter.php(793): MediaWiki\Language\LanguageConverter->recursiveConvertTopLevel()
#6 /srv/wiki.gslin.org/public/includes/language/LanguageConverter.php(781): MediaWiki\Language\LanguageConverter->convertTo()
#7 /srv/wiki.gslin.org/public/includes/parser/Parser.php(1719): MediaWiki\Language\LanguageConverter->convert()
#8 /srv/wiki.gslin.org/public/includes/parser/Parser.php(704): MediaWiki\Parser\Parser->internalParseHalfParsed()
#9 /srv/wiki.gslin.org/public/includes/content/WikitextContentHandler.php(384): MediaWiki\Parser\Parser->parse()
#10 /srv/wiki.gslin.org/public/includes/content/ContentHandler.php(1691): MediaWiki\Content\WikitextContentHandler->fillParserOutput()
#11 /srv/wiki.gslin.org/public/includes/content/Renderer/ContentRenderer.php(79): MediaWiki\Content\ContentHandler->getParserOutput()
#12 /srv/wiki.gslin.org/public/includes/Revision/RenderedRevision.php(263): MediaWiki\Content\Renderer\ContentRenderer->getParserOutput()
#13 /srv/wiki.gslin.org/public/includes/Revision/RenderedRevision.php(236): MediaWiki\Revision\RenderedRevision->getSlotParserOutputUncached()
#14 /srv/wiki.gslin.org/public/includes/Revision/RevisionRenderer.php(239): MediaWiki\Revision\RenderedRevision->getSlotParserOutput()
#15 /srv/wiki.gslin.org/public/includes/Revision/RevisionRenderer.php(172): MediaWiki\Revision\RevisionRenderer->combineSlotOutput()
#16 [internal function]: MediaWiki\Revision\RevisionRenderer->{closure:MediaWiki\Revision\RevisionRenderer::getRenderedRevision():170}()
#17 /srv/wiki.gslin.org/public/includes/Revision/RenderedRevision.php(199): call_user_func()
#18 /srv/wiki.gslin.org/public/includes/poolcounter/PoolWorkArticleView.php(106): MediaWiki\Revision\RenderedRevision->getRevisionParserOutput()
#19 /srv/wiki.gslin.org/public/includes/poolcounter/PoolWorkArticleViewCurrent.php(123): MediaWiki\PoolCounter\PoolWorkArticleView->renderRevision()
#20 /srv/wiki.gslin.org/public/includes/poolcounter/PoolCounterWork.php(171): MediaWiki\PoolCounter\PoolWorkArticleViewCurrent->doWork()
#21 /srv/wiki.gslin.org/public/includes/page/ParserOutputAccess.php(362): MediaWiki\PoolCounter\PoolCounterWork->execute()
#22 /srv/wiki.gslin.org/public/includes/page/Article.php(827): MediaWiki\Page\ParserOutputAccess->getParserOutput()
#23 /srv/wiki.gslin.org/public/includes/page/Article.php(547): Article->generateContentOutput()
#24 /srv/wiki.gslin.org/public/includes/actions/ViewAction.php(78): Article->view()
#25 /srv/wiki.gslin.org/public/includes/actions/ActionEntryPoint.php(733): ViewAction->show()
#26 /srv/wiki.gslin.org/public/includes/actions/ActionEntryPoint.php(510): MediaWiki\Actions\ActionEntryPoint->performAction()
#27 /srv/wiki.gslin.org/public/includes/actions/ActionEntryPoint.php(146): MediaWiki\Actions\ActionEntryPoint->performRequest()
#28 /srv/wiki.gslin.org/public/includes/MediaWikiEntryPoint.php(200): MediaWiki\Actions\ActionEntryPoint->execute()
#29 /srv/wiki.gslin.org/public/index.php(58): MediaWiki\MediaWikiEntryPoint->run()
#30 {main}

What should have happened instead?:

Software version (on Special:Version page; skip for WMF-hosted wikis like Wikipedia):

Other information (browser name/version, screenshots, etc.):
https://www.mediawiki.org/w/index.php?title=Project%3ASupport_desk&curid=2084484&diff=7910916#$wgMainCacheType_=_CACHE_ACCEL;_(i.e._APCU)_causes_PHP_error_on_MW_1.43.3

Details

Other Assignee
cscott

Event Timeline

TheDJ created this task.Sep 29 2025, 11:28 AM
Restricted Application added a subscriber: Aklapper. · View Herald TranscriptSep 29 2025, 11:28 AM
TheDJ updated the task description. (Show Details)Sep 29 2025, 11:30 AM
TheDJ added a project: MediaWiki-libs-BagOStuff.
Restricted Application added a project: MediaWiki-Platform-Team. · View Herald TranscriptSep 29 2025, 11:31 AM
Reedy added a project: MediaWiki-Language-converter.Sep 29 2025, 12:09 PM
Reedy added projects: MW-1.44-release, MW-1.43-release, MW-1.45-release.Sep 29 2025, 12:11 PM
TheDJ renamed this task from APCU + languageconverter error with PHP 8.4 to APCU + languageconverter dynamic property creation error with PHP 8.4.Sep 29 2025, 12:20 PM
JTweed-WMF moved this task from Inbox, needs triage to Next (DO NOT USE) on the MediaWiki-Platform-Team board.Sep 29 2025, 2:39 PM
JTweed-WMF edited projects, added: MediaWiki-Platform-Team (Radar), Content-Transform-Team; removed: MediaWiki-Platform-Team.
Winston_Sung moved this task from Backlog to MediaWiki core on the PHP 8.4 support board.Sep 29 2025, 2:47 PM
Winston_Sung moved this task from MediaWiki core to Backlog on the PHP 8.4 support board.
Winston_Sung moved this task from Backlog to Core on the MediaWiki-Language-converter board.
SLopes-WMF edited projects, added: Content-Transform-Team (Work In Progress); removed: Content-Transform-Team.Oct 2 2025, 2:10 PM
SLopes-WMF updated Other Assignee, added: cscott.
SLopes-WMF moved this task from Backlog to Q4 FY25-26 on the Content-Transform-Team (Work In Progress) board.
cscott subscribed.EditedOct 2 2025, 2:58 PM

This seems to be a bug with apcu_fetch, since ReplacementArray is not doing anything "interesting" here at all, except maybe defining __sleep unnecessarily. The data property is initialized by the constructor and there should be no way to create a ReplacementArray without initializing data.

Tgr subscribed.Oct 2 2025, 3:36 PM

Typing data was done in 1.43 (which would match the mw.org report), so maybe changing the type breaks unserialization somehow?

In any case, not really actionable? I don't think we promise that you can do a major version upgrade without clearing caches.

TheDJ added a comment.EditedOct 2 2025, 6:03 PM

Seems like a logical assessment. Maybe we should think if there is something we can check in the update process to detect and encourage ppl to reset that cache ?

Krinkle subscribed.EditedOct 2 2025, 10:38 PM

We automatically clear db-based object caches as part of update.php. For things stored in APCU, though, it seems reasonable to expect that keys are versioned or validated at runtime. An admin might manually reboot their webserver, but afaik that is not status quo and not documented or indicated as a required upgrade step.

LanguageConverter::loadTables uses the CACHE_VERSION_KEY constant in its makeKey calls. That should be bumped if the value changed in a backwards-incompatible manner.

Tgr added a comment.Oct 3 2025, 1:11 PM

Application logic doesn't know whether it's using SQLBagOStuff or APCU, that's a matter of confiugration.

I see update.php clears the objectcache table manually; that seems both too much (it's used as the default session store when memcache etc. is not installed) and too little. But then there isn't any obvious way to do better; APCU can be purged programmatically but just as with objectcache, it doesn't know what it's being used for so no way to tell whether it should.

Anyway, this is actually a consequence of the renamespacing, not the type hint change: eval1, eval2.

Deprecated: Creation of dynamic property MediaWiki\Language\ReplacementArray::$data is deprecated in /in/AlIPR on line 19
object(MediaWiki\Language\ReplacementArray)#1 (2) {
  ["data":"MediaWiki\Language\ReplacementArray":private]=>
  NULL
  ["data":"ReplacementArray":private]=>
  array(1) {
    [0]=>
    int(1)
  }
}

Apparently this is a known bug: https://github.com/php/php-src/issues/18542

MSantos added a project: Parsoid-Read-Views (Language Converter Support).Oct 9 2025, 2:24 PM
Reedy moved this task from Backlog to MediaWiki core on the PHP 8.4 support board.Oct 11 2025, 9:38 PM
MSantos added a project: OKR-Work.Oct 20 2025, 2:07 PM
MSantos moved this task from Blocker to Not a blocker on the MW-1.45-release board.Oct 21 2025, 3:31 PM
SLopes-WMF moved this task from Q4 FY25-26 to Blocked on the Content-Transform-Team (Work In Progress) board.Oct 27 2025, 3:15 PM
MSantos triaged this task as High priority.Jan 12 2026, 4:07 PM
HakanIST subscribed.Apr 26 2026, 4:58 PM
Content licensed under Creative Commons Attribution-ShareAlike (CC BY-SA) 4.0 unless otherwise noted; code licensed under GNU General Public License (GPL) 2.0 or later and other open source licenses. By using this site, you agree to the Terms of Use, Privacy Policy, and Code of Conduct. · Wikimedia Foundation · Privacy Policy · Code of Conduct · Terms of Use · Disclaimer · CC-BY-SA · GPL · Credits