Starting on December 1st 2016, foreachwikiindblist sends one cronspam email per day explaining how to get debug information:
From: Cron Daemon <root@terbium.eqiad.wmnet> Date: Thu, 01 Dec 2016 00:06:02 +0000 To: www-data@terbium.eqiad.wmnet Subject: Cron <www-data@terbium> /usr/local/bin/foreachwikiindblist /srv/mediawiki/dblists/echo.dblist extensions/Echo/maintenance/processEchoEmailBatch.php >/dev/null Message-Id: <E1cCEt0-0003b9-Mm@terbium.eqiad.wmnet> Set $wgShowDBErrorBacktrace = true; at the bottom of LocalSettings.php to show detailed debugging information