app-misc/gourmet-0.15.4-r1 was last touched 13 July 2010 and seems to be working fine. Additionally, I think it uses the python eclass better and has more accurate deps than 0.15.4. I'd like to keep this version around instead of 0.15.4 while some bugs are worked out of more recent versions.
Tested on x86 all good here.
Why do you want this version around since 0.15.6 is stable anyway?
I guess it doesn't matter any more since arfrever decided to delete all the older versions. I was a little bit concerned about the stability of anything past 0.15.4 and I didn't want users to have unusable recipe databases. If I see any bug reports about it, I'll have to bring it back and reopen this bug.