Last modified: 2014-02-24 11:20:47 UTC
Jenkins should set $wgDevelopmentWarnings = true, and keep a count of E_USER_DEPRECATED errors in the PHP error log that are generated by the test suite. If a patch causes that number to go up, Jenkins should -1 it.
Adding $wgDevelopmentWarnings = true was bug bug 38882, it was no more applied until I refactor the way we inject MediaWiki settings in build ( https://gerrit.wikimedia.org/r/#/c/89837/ ). Long story short, the setting is enabled since roughly Oct 15 2013. I am not sure whether a E_USER_DEPRECATED warning would throw an exception though. Might want to write a test case and see what happens.