don't know which session failed

Hey,

I'm getting an error such as this:

```
Dec 05 11:48:04 ananke nitter[894994]: Fetch error, API: userScreenName, errors: (errors: @[(code: couldntAuth, mess
age: "Could not authenticate you")])
```

Could you possibly add an identifier as to which session fails? Best for both `kind == "cookie"`and `kind == "oauth"`.