You mean this?
```diff
-    raise Response(400, {"error": str(e)})
+    raise Response(400, unicode(e))
```

Is there a better way to do it?

When doing a "real" request, you get JSON like this back:
```json
{
  "error_code": 400,
  "error_message_short": "Bad Request",
  "error_message_long": "The username '¶' contains invalid characters."
}