Current situation:
In recent past had often happened that ego synced version of kits produced unbuildable system. Or another rationale, if older version is more favorable to newer (for multiple reasons). Plus with new way the kits generator works, only the most recent version in many cases is kept. Also it seems that 1.3 is kept anymore, so there is no stable version (as it seems to me, I can be wrong). There is of course work around, checking out commit after commit each repos/kit/package to find out which version is actually working. As you can imagine this can be pretty tiresome...

Proposal:
Add date_fix variable to /etc/ego.conf that will checkout most recent version before that fix (or freeze) date. This has advantage that if you knew you had working system version few months back, you can roll back to that date/version with everything working and wait until upstream version is available. It is also easier to regress back in time with this mechanism, since you get consistent snapshot to certain date.

I have prototype ready if you are interested...