Hello Ian, all,
Roland, when you uploaded the osx-sierra results, did you use homebrew or macports?
The results in the testsuite page http://einsteintoolkit.org/release-info/parse_testsuite_results.php are for OSX Sierra Homebrew (should have added that to the name as well).
Note: I don't know if gcc 4.6 will actually be sufficient. We need some c++11 features and 4.6 is so very old that I am not sure if they are supported.
Yours, Roland