When I add a PSR-4 block to the repository composer.json, with or without an update of the autoloader (we need it), the operations-mw-config-composer-hhvm-jessie Jenkins job want to dump a new list.
To do it, it needs to touch the wmf-config/PrivateSettings.php file.
Currently, the file doesn't exist, so test fails:
Job console output
02:38:56 Dependency resolution completed in 0.002 seconds 02:38:56 Writing lock file 02:38:56 Generating optimized autoload files 02:38:57 02:38:57 Installation failed, reverting ./composer.json to its original content. 02:38:57 02:38:57 02:38:57 [RuntimeException] 02:38:57 File at "/home/jenkins/workspace/operations-mw-config-composer-hhvm-jessie/wmf-config/PrivateSettings.php" does not exist, check your classmap definitions