dev-libs/fcgi-2.0.4-r2 is the stable version for fcgi on all platforms except amd64. I'm not sure why amd64 is behind the curve here (couldn't find an earlier stabilization bug), but I think it makes sense for amd64 to also mark fcgi-2.0.4-r2 as stable. No open bugs, and this particular revision has been in the tree since january.
I assume you really meant dev-libs/fcgi-2.4.0-r2?
Bah :-( Yes, I did mean 2.4.0-r2. At least I was consistent in my misguidedness. Thanks for the correction.
amd64 done