It appears that the hard version in the Makefile just hasn't been incremented since v6.6.80, the first 'release' on the repo, and every version from then until now (v7.10.0) has it. This compiled v6.6.80 seems to be in parity function-wise with v7.10.0.
I'll just need to figure out how to set up the branding environment to make any headway. The final deb/rpm/tgz Makefiles appear to be using branding and sed to configure and name the packages.
Looking over everything, all of the vital binaries seem to be there, though they build into v6.6.8 when current is v7.9. Other than that, it builds just fine in a clean Go dev environment. I'll have to test later to see if they function as expected and do some comparisons.
If they function, I'll fork and get it going as a Linux-only tool, since the Windows tools are being removed. Will that work?
Is the guest-tools.iso in the XCP-ng fork anywhere (I can't seem to find it)?
There are some changes to the Linux install scripts that I would like to contribute, specifically regarding CoreOS (Container Linux).