make installcheck fails against a server running with operator_precedence_
warning = on.
The difference is in update.out, and consists of an error-locating carat getting moved over by one position. I've attached the regression diff.
I don't know why the setting of this GUC causes the carat to move around, that seems odd. If it can't be fixed at the source, it should be easy enough to just override the setting in update.sql.
Cheers,
Jeff
