This looks correct to me, I don't really understand your point in why you think this is a bug:
LOG.debug('Checking root disk injection %(info)s', info=str(injection_info), instance=instance)
This looks correct to me, I don't really understand your point in why you think this is a bug:
LOG.debug('Checking root disk injection %(info)s',
info= str(injection_ info), instance=instance)