Session variable does not work as expected in 7.0

[1d2u3c]

mysql> update User set State=(@A := 2) where UserID = 134;
ERROR 1105 (HY000): vtgate: http://ourtest:15001/: syntax error at position 28 near ':'

[1d2u3c]

The problem appears to be that the Vitess parser isn't recognizing the := syntax. Possibly related to this line of code: https://github.com/vitessio/vitess/blob/master/go/vt/sqlparser/token.go#L546

Also here:
https://github.com/vitessio/vitess/blob/master/go/vt/sqlparser/sql.y

[1d2u3c]

According to discussion of this issue on Vitess Slack with the devs, the assignment operator is not supported. Closing this issue.