> "in my world, where linux doesn't exist" ... we have this exact problem
> with vendor software, that will *only* run on a particular release of
> the host OS.

Right, so it doesn't run if the vendor O.S. version is 1.3, does it?
:')

> i'm now not sure if i like the "setuname" vs. the "sysctl for each
> emulation" ideas.  perhaps both can be used ....

You almost need a per-binary wrapper to deal with the problem you're
describing.   Needless to say, "yuck."

			       _MelloN_