dbtest repl error

[DH]

Hi,

I'm running MongoDB 3.4 with a custom filesystem and able to run all dbtests except this one:

$ ./dbtest repl

...

2017-01-07T13:16:36.903-0800 I STORAGE  [testsuite] Starting WiredTigerRecordStoreThread local.oplog.$main

2017-01-07T13:16:36.903-0800 I STORAGE  [testsuite] The size storer reports that the oplog contains 0 records totaling to 0 bytes

2017-01-07T13:16:36.903-0800 I STORAGE  [testsuite] Scanning the oplog to determine where to place markers for truncation

2017-01-07T13:16:37.005-0800 I -        [testsuite] going to run suite: repl

2017-01-07T13:16:37.005-0800 I -        [testsuite]      going to run test: ReplTests::LogBasic

2017-01-07T13:16:37.016-0800 E -        [testsuite] Throwing exception: Expected 2 == opCount() (2 == 0) @src/mongo/dbtests/repltests.cpp:266

2017-01-07T13:16:37.025-0800 I -        [testsuite] FAIL: ReplTests::LogBasic   Expected 2 == opCount() (2 == 0) @src/mongo/dbtests/repltests.cpp:266

2017-01-07T13:16:37.025-0800 I -        [testsuite]      going to run test: ReplTests::Idempotence::InsertTimestamp

...

What could the problem be that opCount() is 0?  I'm trying to debug using gdb and would appreciate any tips.

Thanks,

DH