Redmine

I'm getting a non-fatal error when running bundle install. It is:
spec failed yard not installed (gem installed yard)

I've looked here in the forums and found nothing as well as nothing on Google directly addressing this.
I've tried to install the gem yard and it doesn't make any difference.
I've also tried installing yard (apt-get install yard) and the gem but then it completely clobbers the install resulting in a barrage of top errors.

Any help would be appreciated.