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/pipeline/document_source_list_sessions.h:122: UNINIT_CTOR 115076 Class member declaration for "_allUsers".
/src/mongo/db/pipeline/document_source_list_sessions.h:54: UNINIT_CTOR 115076 Non-static class member "_allUsers" is not initialized in this constructor nor in any functions that it calls.