Created attachment 318722 [details] emerge fail log =sys-apps/coreutils-8.17 fails tests with clang-3.1-r4, latest stable (8.14) fails also, I didn't test intermediate versions.
Tests fail with GCC 4.6.3 also (might not be a clang-related issue).
Fixing tests is an upstream issue, which is beyond the scope of what we can do at this time.