[gentoo-user] Bisect a problem going back months?

[Mark Knecht <markknecht@gmail.com>]

I'm wondering if there is a Gentoo way to bisect a bug that's crept
into my 64-bit Intel-based system (Intel process, motherboard and
graphics) over the last few months. Fundamentally when this bug
appears it generates a complete X crash back to the gdm login. My
suspicion is that it's related to the Gentoo push to use firefox-bin
and 32-bit Flash until some security issues were addressed but I don't
know that for sure.

Are there specific overlays I'd want to add using layman that would
allow me to get back to earlier versions of the Intel graphics driver,
64-bit Firefox and the now masked versions of Flash I was using say
2-3 months ago? At this point I don't know for sure that what I need
isn't in portage and just masked. I'll start reviewing that this
evening. This post was primarily just to figure out what my options
might be.

I've never used sunrise or sunset, etc. Maybe it's as easy as adding
one of those to layman and then bisecting my way through some
experiments to figure out where the problem first appeared?

Thanks,
Mark