Logging in at https://wikitech.wikimedia.org/ with a (correct) username/password but no token results in the following:
Exception encountered, of type "Exception"
Description
Description
Event Timeline
Comment Actions
2015-10-29 23:38:26 silver labswiki exception ERROR: [9d20f3e6] /w/index.php?title=Special:UserLogin&action=submitlogin&type=login&returnto=Statsd Exception from line 788 of /srv/mediawiki/php-1.27.0-wmf.4/includes/specials/SpecialUserlogin.php: Invalid status code returned from AbortLogin hook: 8 {"exception_id":"9d20f3e6"}
[Exception Exception] (/srv/mediawiki/php-1.27.0-wmf.4/includes/specials/SpecialUserlogin.php:788) Invalid status code returned from AbortLogin hook: 8
#0 /srv/mediawiki/php-1.27.0-wmf.4/includes/specials/SpecialUserlogin.php(968): LoginForm->authenticateUserData()
#1 /srv/mediawiki/php-1.27.0-wmf.4/includes/specials/SpecialUserlogin.php(345): LoginForm->processLogin()
#2 /srv/mediawiki/php-1.27.0-wmf.4/includes/specialpage/SpecialPage.php(384): LoginForm->execute(NULL)
#3 /srv/mediawiki/php-1.27.0-wmf.4/includes/specialpage/SpecialPageFactory.php(553): SpecialPage->run(NULL)
#4 /srv/mediawiki/php-1.27.0-wmf.4/includes/MediaWiki.php(248): SpecialPageFactory::executePath(Title, RequestContext)
#5 /srv/mediawiki/php-1.27.0-wmf.4/includes/MediaWiki.php(669): MediaWiki->performRequest()
#6 /srv/mediawiki/php-1.27.0-wmf.4/includes/MediaWiki.php(474): MediaWiki->main()
#7 /srv/mediawiki/php-1.27.0-wmf.4/index.php(41): MediaWiki->run()
#8 /srv/mediawiki/w/index.php(3): require(string)
#9 {main}