The wikimedia/iegreview project is using a PSR-4 autoloading scheme (just like PSR-0 except you don't have to have a bunch of empty directories in your path to define the full namespace).

The phpunit job for this repository is failing with this error:

PHP Fatal error: Call to undefined method Composer\Autoload\ClassLoader::setPsr4() in /srv/ssd/jenkins-slave/workspace/wikimedia-iegreview-phpunit/vendor/composer/autoload_real.php on line 33
PHP Stack trace:
PHP 1. {main}() /srv/deployment/integration/phpunit/vendor/phpunit/phpunit/composer/bin/phpunit:0
PHP 2. PHPUnit_TextUI_Command::main() /srv/deployment/integration/phpunit/vendor/phpunit/phpunit/composer/bin/phpunit:63
PHP 3. PHPUnit_TextUI_Command->run() /srv/deployment/integration/phpunit/vendor/phpunit/phpunit/PHPUnit/TextUI/Command.php:129
PHP 4. PHPUnit_TextUI_Command->handleArguments() /srv/deployment/integration/phpunit/vendor/phpunit/phpunit/PHPUnit/TextUI/Command.php:138
PHP 5. PHPUnit_TextUI_Command->handleBootstrap() /srv/deployment/integration/phpunit/vendor/phpunit/phpunit/PHPUnit/TextUI/Command.php:606
PHP 6. PHPUnit_Util_Fileloader::checkAndLoad() /srv/deployment/integration/phpunit/vendor/phpunit/phpunit/PHPUnit/TextUI/Command.php:778
PHP 7. PHPUnit_Util_Fileloader::load() /srv/deployment/integration/phpunit/vendor/phpunit/phpunit/PHPUnit/Util/Fileloader.php:76
PHP 8. include_once() /srv/deployment/integration/phpunit/vendor/phpunit/phpunit/PHPUnit/Util/Fileloader.php:92
PHP 9. require() /srv/ssd/jenkins-slave/workspace/wikimedia-iegreview-phpunit/tests/bootstrap.php:24
PHP 10. ComposerAutoloaderInit219a9bfa76f2ac9b53cf75ea98d99ffa::getLoader() /srv/ssd/jenkins-slave/workspace/wikimedia-iegreview-phpunit/vendor/autoload.php:7

After a lot of head scratching I figured out that this is caused by the vendor/composer/ClassLoader.php that is loaded from the integration/phpunit project to run phpunit. This older version of the \Composer\Autoload\ClassLoader class shadows the newer version present in wikimedia/iegreview/vendor/composer/ClassLoader.php.

The fix for this should be as easy as regenerating the classloader for the integration/phpunit project using a newer version of Composer that supports PSR-4 autoloaders.

Version: wmf-deployment
Severity: normal