The version field in /usr/lib{,64}/pkgconfig/libproxy-1.0.pc is empty, causing configure checks to fail in some other packages that depend on it.
This doesn't seem to be fixed upstream. Given that there is an ABI bump with libmodman that prevent an update I can only update rawhide from any later upstream version. So even If I fix this 0.4.4 version, it will be unreliable to use that field before that future version. I'm looking at fixing that upstream for now.
http://code.google.com/p/libproxy/issues/detail?id=151
Workarounded in libproxy-0.4.6-3.fc15, Fix awaited from upstream in next release.
*** Bug 664781 has been marked as a duplicate of this bug. ***
*** Bug 674854 has been marked as a duplicate of this bug. ***