I posted a possible solution, it seems to work if you disable:

require( dirname( __FILE__ ) . '/SearchFeed.i18n.php' );
                foreach ( $allMessages as $lang => $langMessages ) {
                        $wgMessageCache->addMessages( $langMessages, $lang );
                }

From the loadMessages() method in Search_body.php

I just used the code..

function loadMessages() {
                static $messagesLoaded = false;
                global $wgMessageCache;
                if ( $messagesLoaded ) return;
                $wgMessageCache->loadAllMessages();
                return true;
        }

fwiw