Andy – Some ideas. Not sure if they are helpful.
Can you confirm that /etc/sudoers.d is a directory and not a file.
The error message is somewhat confusing.
Do you have the option to use CentOS 6?
Are you able to list the files within those two RPMs? I am intrigued to know what the difference is. I assume that ambari-agent is only inserting a file within the /etc/sudoers.d directory and not modifying the directory itself….
PS Ambari 2.0.1 is a possibility as is *I think* sticking with Ambari 1.7.