Can't start up a 'thin' server in Rails; 'listening on http://0.0.0.0:3000/' gives error page

I'm not sure how to debug this: if I run the regular rails server with rails s, I get an SSL Protocol error on localhost, and if I run thin start --ssl, I get an empty response.

Ideally I'd like to start a server with https:// so I can use Omniauth with a bunch of websites like Facebook.