The [[ https://gerrit.wikimedia.org/g/mediawiki/core/+/master/maintenance/purgeParserCache.php | purgeParserCache.php ]] maintenance script is failing intermittently, with output that looks like this: P10981
The error at the end is
```
Apr 14 20:43:25 mwmaint1002 mediawiki_job_parser_cache_purging[210524]: Cannot purge this kind of parser cache.
```
followed by exit status 1. This happens on some runs, but not all; the rest finish successfully.
I've been converting maintenance cronjobs to systemd timers, which means among other things we actually get notified when they fail -- so it's entirely possible this has been happening for a while now.
[Source: maintenance/purgeParserCache.php#75](https://gerrit.wikimedia.org/g/mediawiki/core/+/c260233ff98d65359c447e3c60122a9c5139e78c/maintenance/purgeParserCache.php#75)
```lang=php
$pc = MediaWikiServices::getInstance()->getParserCache()->getCacheStorage();
$success = $pc->deleteObjectsExpiringBefore( $date, [ $this, 'showProgressAndWait' ] );
if ( !$success ) {
$this->fatalError( "\nCannot purge this kind of parser cache." );
}
```