The microformats parser will crash when url.Parse returns an error. The "parsed" will be nil and this will crash inside ResolveReference.

I found it while parsing: https://chat.indieweb.org/dev/2018-04-17. This will also crash when run with gomf https://chat.indieweb.org/dev/2018-04-17

https://github.com/willnorris/microformats/blob/bc552049783fddac99a36ffb65bf3c99f12b64d7/microformats.go#L226