There are a few changes in glibc-2.10 that might make your software fail to build with it, please refer to my blog post  if you're not sure what the problem is. Also make sure to fix it rather than sidestepping the issue .
And no I don't usually provide emerge --info with these bugs because they are caused by glibc-2.10!
Created attachment 196892 [details]
Fixed, thanks Diego. And I believe I have fixed it the right way. ;o)