Harbormaster: Build failure on OS/X build. How to fix it as a non Mac user

Hi all, Phabricator informed me, that the builds on Harbourmaster for my changes failed.  Looking at the log at https://phabricator.haskell.org/B21368 I can see, that the builds on Linux and Windows succeeded, however the tests on OS/X failed. Looking at the failed tests at https://phabricator.haskell.org/harborma ster/build/48354/ it tells me that the 2 tests TEST="T5631 T6048" failed. Now, I don't own a machine with OS/X. How can I look, what really failed, and how can I try to fix it? Many thanks Roland