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/ix_scan.h:119: UNINIT_CTOR 120188 Class member declaration for "_catalogEpoch".
/src/mongo/db/exec/sbe/stages/ix_scan.cpp:69: UNINIT_CTOR 120188 Non-static class member "_catalogEpoch" is not initialized in this constructor nor in any functions that it calls.