internal/testutil/testutil.go

@@ -119,6 +119,10 @@ type describer struct {
 }
 
 func (this *describer) describe(value reflect.Value) {
+	if !value.IsValid() {
+		this.printf("<invalid>")
+		return
+	}
 	value = reflect.ValueOf(value.Interface())
 	switch value.Kind() {
 	case reflect.Array, reflect.Slice: