Uninitialized scalar field
The field will contain an arbitrary value left over from earlier computations. A scalar field is not initialized by the constructor
/src/mongo/db/storage/ephemeral_for_test/ephemeral_for_test_sorted_impl.cpp:846: UNINIT_CTOR 115964 Class member declaration for "_reversePos".
/src/mongo/db/storage/ephemeral_for_test/ephemeral_for_test_sorted_impl.cpp:807: UNINIT_CTOR 115964 Non-static class member "_reversePos" is not initialized in this constructor nor in any functions that it calls.