Xcode 4.3 changed a lot. Most notably, all the stuff that was once under /Developer now resides under /Application/Xcode.app/Contents/Developer. And the SDKs have moved under the *.platform subdirectories. This breaks a lot of stuff. Especially auto-detecting build systems, such as boost jam. Will write back when I have some work arounds…
Update: I prepared a quick-fix for boost, so it compiles with Xcode 4.3 and builds the framework (see boost ticket #6686. However, I still get compile errors in my project, since clang is very picky and complains about boost:
I think this might be a genuine boost bug. It’s probably already known, but I haven’t checked. Will post another update when I find something.
The quick fix is also available in my github repo, see here.
Update 2: This is a known error, and it has been fixed in later revisions of boost (I am using 1.48 right now). The solution here is that instead of size, there should be size_arg. I wonder how this could ever have worked…