Description of Drivers Ticket:

MongoDB 4.4 introduces a new "provenance" field to write concern errors, which describes the origin of the write concern associated with the error. For example:

"writeConcernError" : {
    "code" : 64,
    "codeName" : "WriteConcernFailed",
    "errmsg" : "waiting for replication timed out",
    "errInfo" : {
        "wtimeout" : true,
        "writeConcern" : {
            "w" : 2,
            "wtimeout" : 1000,
            "provenance" : "clientSupplied"
        }
    }
}

Though drivers should not parse the "errInfo" field of a writeConcernError, drivers must ensure that the provenance field is accessible to users so that developers/admins can be aware of situations such as custom write concern defaults causing wtimeouts, etc.

SPEC-1578 makes explicit how a WriteConcernError should be constructed from a server reply. Drivers need to validate (or update if necessary) the logic for constructing WriteConcernError,  and implement a new prose test to validate a "provenance" is accessible from a WriteConcernError.
See DRIVERS-967 for updated details.