If you use the serialized hooks cache introduced by
request #12475, the Git post receive hook does not start.
Trace:
$ DISPLAY_ERRORS=true /usr/share/tuleap/src/utils/php-launcher.sh /usr/share/tuleap/plugins/git/hooks/post-receive.php
PHP Fatal error: Class 'GitDao' not found in /usr/share/tuleap/plugins/git/hooks/post-receive.php on line 38