Comment 4 for bug 1831911

Still seeing this failure in master promotions:

2019-06-07 02:28:08.536 9 ERROR ironic.drivers.modules.agent_base_vendor [req-2e80ee1f-ae6e-4e01-8be4-087e85e28a8e - - - - -] Failed to install a bootloader when deploying node d31a2f95-0649-4681-a381-37ff0e5d61f0. Error: {u'message': u'[Errno 2] No such file or directory', u'code': 500, u'type': u'OSError', u'details': u''}

https://review.opendev.org/#/c/663361/ merged the day before:
Jun 6 10:31 PM