Since the various changes [1] introduced in the Job Queue handling during normal page requests, it caused a lot of problems [2] on installations where the on-request job queue is being used (not on WMF wikis, of course, that's why it went unnoticed until 1.22 was released).
The old way of handling the job queue is still present, and will be used if $wgPhpCli is not set to an actual path, or safe mode is on. But still, there's no other way for wikis to revert to the old way unless setting $wgPhpCli to false or an empty string, which may be used for something else and cause other undesired side-effects.
We should introduce a configuration setting (for example, $wgUseOldOnRequestJobQueueHandling = true) to revert the job queue handling without interfering with $wgPhpCli, which should default to the old job queue handling, until those issues are fixed, while letting developers and experienced sysadmins enable this *experimental* (at best) feature.
[1] https://www.mediawiki.org/wiki/Manual:Job_queue#Changes_introduced_in_MediaWiki_1.22
Version: 1.22.0
Severity: normal