MySQL copyfrom throws "can't encode type models.ExperienceLocationsType to TSV" if models.ExperienceLocationsType is a string enum

type ExperienceLocationsType string

const (
	ExperienceLocationsTypeStartPoint      ExperienceLocationsType = "start_point"
	ExperienceLocationsTypePickupPoint     ExperienceLocationsType = "pickup_point"
	ExperienceLocationsTypeRedemptionPoint ExperienceLocationsType = "redemption_point"
	ExperienceLocationsTypeEndPoint        ExperienceLocationsType = "end_point"
)

can't encode type models.ExperienceLocationsType to TSV

create table experience_locations
(
    location_id   varchar(512)                                                          not null,
    type          enum ('start_point', 'pickup_point', 'redemption_point', 'end_point') not null
)

-- name: UpsertExperienceLocations :copyfrom
REPLACE INTO experience_locations (location_id, type)
VALUES (?, ?);

version: "2"

sql:
  - engine: mysql
    schema: migrations
    queries: queries
    gen:
      go:
        package: models
        sql_package: "database/sql"
        sql_driver: "github.com/go-sql-driver/mysql"
        out: models