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 .
And no I don't usually provide emerge --info with these bugs because they are caused by glibc-2.10!
Created attachment 197856 [details]
The patch has been added to CVS.
By the way, USE information would have been helpful as it was only failing with a specific USE flag. I agree, build log has configure line but USE flags are more friendly ;)