check.report(err)
}
-func (check *Checker) versionErrorf(at positioner, v version, format string, args ...interface{}) {
+func (check *Checker) versionErrorf(at positioner, v goVersion, format string, args ...interface{}) {
msg := check.sprintf(format, args...)
var err *error_
err = newErrorf(at, UnsupportedFeature, "%s requires %s or later", msg, v)