The issue can be seen here:
http://neovim-qb.szakmeister.net/build/2883/tap_report/by_test?reportset=functionaltest-macosx-64-release
If you try clicking on the log, it just brings you to the same page. Prior to 6.0.27, it would take you to an error screen (because something about it was broken). I was going to file an official bug report on it today and discovered the new behavior. I did submit the other issue via the button on the error screen before though.
Either way, it doesn't show the necessary bits (the output of the test about what failed).