The Arcanist's unit test called ArcanistPhpcsLinterTestCase always exploded as far as I remember. Nobody cared. Let's file a task.
$ arc unit ./src/lint/linter/__tests__/ArcanistPhpcsLinterTestCase.php PASS 33ms★ ArcanistPhpcsLinterTestCase::testVersion FAIL ArcanistPhpcsLinterTestCase::testLinter Lint emitted an unexpected set of messages for file "basics.lint-test". MISSING MESSAGES Message with severity "error" at "2:1" Message with severity "error" at "3:1" Message with severity "error" at "3:14" Message with severity "error" at "4:3" Message with severity "error" at "6:3" SURPLUS MESSAGES (No messages.)