Summary: (Technical explanation: the `PhabricatorTestCase` class includes extra code to setup the Phabricator config system. Originally remarkup was part of the libphutil repo and didn't depend on any Phab stuff. Phorge broke this rule that had no reason to exist anymore T15161, but didn't update the test, resulting in this extremely silly edge case ...) Fixes T15973 (and sorry @valerio.bozzolan for stealing a ticket from you for the third time in the last few days) Test Plan: Run `arc unit src/infrastructure/markup/__tests__/PhutilRemarkupEngineTestCase.php` Reviewers: O1 Blessed Committers, aklapper, valerio.bozzolan Reviewed By: O1 Blessed Committers, aklapper, valerio.bozzolan Subscribers: aklapper, tobiaswiese, Matthew, valerio.bozzolan, Cigaryno Maniphest Tasks: T15973 Differential Revision: https://we.phorge.it/D26662