An automated test failed on OS X on the csuite/wt2909_checkpoint_integrity test.
The failing output is not very helpful. There are no errors in the stdout.txt in the database directory.

[2017/08/29 00:25:59.888] ../../build_posix/gnu-support/test-driver: line 107: 60693 Abort trap: 6           "$@" > $log_file 2>&1
[2017/08/29 00:25:59.890] FAIL: test_wt2909_checkpoint_integrity

My repro attempts on AWS have not failed in over 24 hours.