beachboy4231 wrote:
I do have display_errors On, but nothing is outputted. The browser doesn't get a 500, but rather the page source is blank.
I'm talking about the situation where the page source is blank, and it also has a 500 status code. When a well-behaved application needs to send a 500 response, it also sends an explanatory error message as the response body. PHP is not well-behaved in this way, it sends a 500 status code and a blank body, which looks in your browser to be the same as any other blank page. You can tell the difference with the LiveHTTPHeaders extension for Firefox.
The output of display_errors can be lost under various circumstances, such as when there is an out-of-memory error when a custom output buffer is enabled. Try disabling MediaWiki's custom output buffer by putting this in LocalSettings.php:
define( 'MW_NO_OUTPUT_BUFFER', 1 );
-- Tim Starling