I have experienced already several reports of people in mediawiki.org's Project:Support_desk and extensions talk pages about getting weird "Strict Standards" errors.
One of those errors is:
Strict Standards: date_default_timezone_get(): It is not safe to rely on the system's timezone settings
This happens because since PHP >= 5.4.0, E_STRICT became part of E_ALL in error_reporting, and seeing how many people are asking for help about this (in general, not only for MediaWiki) on internet makes me think it's a common environment on many systems.
Having a check on the installer to detect this configuration and issue a warning like "Your PHP configuration includes E_STRICT in error_reporting. This is not a recommended setting for production environments" should help people to early-identify this problem.
On an ideal world, MediaWiki shouldn't issue a E_STRICT under any circumstance. But it seems it's not always possible (being the date_default_timezone_get() an example because of a misconfigured PHP), and some extensions may issue some of them also.
Version: 1.21.x
Severity: enhancement
URL: http://www.mediawiki.org/wiki/Thread:Project:Support_desk/Installation,