The define for the TransactionTooLargeForCache error message is named in a misleading way.

// From src/third_party/wiredtiger/src/include/txn.h
#define WT_TXN_ROLLBACK_REASON_TOO_LARGE_FOR_CACHE \
    "transaction is too large and will not fit in the storage engine cache"

1. No such define exists in the wiredtiger source code
2. The WT prefix implies that this is a WT-specific error message, which it is not. It's a MongoDB error