errors.Format does not crash when formatting normal error

errors/errors.go

@@ -50,12 +50,12 @@ func Errorf (position Position, format string, variables ...any) Error {
 // because normal error messages do not produce trailing line breaks, neither
 // does this function.
 func Format (err error) string {
-	if err, ok := err.(Error); ok {
+	if e, ok := err.(Error); ok {
 		return fmt.Sprintf (
 			"%v: %v\n%v",
-			err.Position(),
-			err.Error(),
-			err.Position().Format())
+			e.Position(),
+			e.Error(),
+			e.Position().Format())
 	} else {
 		return err.Error()
 	}