EXCEPTION (RuntimeException): Undefined variable: output #0 /core/data/drydock/workingcopy-89/repo/phabricator/src/applications/diffusion/protocol/__tests__/DiffusionMercurialCommandEngineTests.php(20): PhutilErrorHandler::handleError(8, 'Undefined varia...', '/core/data/dryd...', 20, Array) #1 [internal function]: DiffusionMercurialCommandEngineTests->testFilteringDebugOutput() #2 /core/data/drydock/workingcopy-89/repo/arcanist/src/unit/engine/phutil/PhutilTestCase.php(493): call_user_func_array(Array, Array) #3 /core/data/drydock/workingcopy-89/repo/arcanist/src/unit/engine/PhutilUnitTestEngine.php(69): PhutilTestCase->run() #4 /core/data/drydock/workingcopy-89/repo/arcanist/src/unit/engine/ArcanistConfigurationDrivenUnitTestEngine.php(148): PhutilUnitTestEngine->run() #5 /core/data/drydock/workingcopy-89/repo/arcanist/src/workflow/ArcanistUnitWorkflow.php(170): ArcanistConfigurationDrivenUnitTestEngine->run() #6 /core/data/drydock/workingcopy-89/repo/arcanist/scripts/arcanist.php(419): ArcanistUnitWorkflow->run() #7 {main}