Ceph

I'm not sure what the exact problem is, but when attempting to build Ceph on arm I had issues with the configure script failing to detect the boost spirit library. It turns out the error was because g++ wasn't installed, or at least didn't resolve to anything. There are checks for g++ and they are done earlier than the checks for boost spirit, but either the configure script doesn't fail out of them, or else it adds search paths to find the executable that some of the other tests don't run.