An automated test failed when running with currently unsupported LSM backing data store.

The test command that triggered a failure is:

python buildscripts/resmoke.py --executor=jstestfuzz_sharded --numClientsPerFixture 10 --wiredTigerCollectionConfig=type=lsm --wiredTigerIndexConfig=type=lsm 

The failure does not readily reproduce.

The failure indicates that there are duplicate entries in an index:

{ "_id" : 1, "x" : 0.7389655158589513 }
{ "_id" : 1, "x" : 0.7389655158589513 }