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/exec/sbe/stages/column_scan.h:241: UNINIT_CTOR 128677 Class member declaration for "_rowId".
/src/mongo/db/exec/sbe/stages/column_scan.cpp:77: UNINIT_CTOR 128677 Non-static class member "_rowId" is not initialized in this constructor nor in any functions that it calls.