I run <code>maintenance/runJobs.php regulary but when I set $wgCacheDirectory (which itself works fine) I get the error

Unable to open DB file for write "/tmp/cacheMsg/l10n_cache-en.cdb"
Backtrace:
#0 includes/Cdb.php(62): CdbWriter_DBA->construct('/tmp/cacheMsg/l...')
#1 includes/LocalisationCache.php(883): CdbWriter::open('/tmp/cacheMsg/l...')
#2 includes/LocalisationCache.php(613): LCStore_CDB->startWrite('en')
#3 includes/LocalisationCache.php(352): LocalisationCache->recache('en')
#4 includes/LocalisationCache.php(262): LocalisationCache->initLanguage('en')
#5 includes/LocalisationCache.php(205): LocalisationCache->loadItem('en', 'magicWords')
#6 languages/Language.php(1946): LocalisationCache->getItem('en', 'magicWords')
#7 languages/Language.php(1960): Language->getMagicWords()
#8 [internal function]: Language->getMagic(Object(MagicWord))
#9 includes/StubObject.php(58): call_user_func_array(Array, Array)
#10 includes/StubObject.php(121): StubObject->_call('getMagic', Array)
#11 [internal function]: StubContLang->call('getMagic', Array)
#12 includes/MagicWord.php(259): StubContLang->getMagic(Object(MagicWord))
#13 includes/MagicWord.php(197): MagicWord->load('rmatch')
#14 includes/parser/Parser.php(4289): MagicWord::get('rmatch')
#15 extensions/RegexFunctions/RegexFunctions.php(49): Parser->setFunctionHook('rmatch', Array)
#16 [internal function]: wfRegexFunctions()
#17 includes/Setup.php(370): call_user_func('wfRegexFunction...')
#18 maintenance/doMaintenance.php(86): require_once('/var/www/vhosts...')
#19 maintenance/runJobs.php(103): require_once('/var/www/vhosts...')
#20 {main}

Tested on MW 1.16a, someone please test for others

Version: unspecified
Severity: normal