Buildfarm vs. Linux Distro classification

Lately there have been some buildfarm registrations for "Debian 
testing/unstable" or similarly described machines. I have kicked back 
against these, as the description seems to me to be far too open ended. 
Likewise, I also have difficulty with Gentoo because a version there 
seems to describe a build system but not any reasonably bounded set of 
software.  The whole point of classifying buildfarm machines is so that 
we can pin down problems to some class of machines, so I'm not really 
sure what I should do in these cases that essentially represent highly 
mobile targets.

Thoughts?

cheers

andrew