Daniel,
downloaded and run it in a mac with no major issues:
$ uname -a
Darwin iMac 14.5.0 Darwin Kernel Version 14.5.0: Wed Jul 29 02:26:53 PDT 2015; root:xnu-2782.40.9~1/RELEASE_X86_64 x86_64
$ make -C build/tests/ show-fails
tail -n 8 regressions.log | head -n 6
EFORMAT-0002-TRANSCODE-READ-CHAR
1 out of 98 total tests failed: MBOX-1-TO-N-BLOCKING.
real time : 92.512 secs
run time : 51.462 secs
gc count : 52 times
consed : 26965205664 bytes
But I see the regressions are the only tests included, so find attached this patch to update the README file for your review and applying.
I pushed it to the repo, but decided to revert it as I still don't get how to use gitlab without messing with the branch.