Google OAuth2 not working on local development server - PHP Codeigniter spark

Google OAuth2 not working on local development server - PHP Codeigniter spark

I am trying to use the Codeigniter spark (
http://getsparks.org/packages/oauth2/versions/HEAD/show) to allow users to
login to my php site with fb and google.
My local dev site (on wampserver) is called mysite.dev, for which I have a
etc/hosts file like :
127.0.0.1 mysite.dev
Facebook login works absolutely fine. But when I try logging with google,
google complains : Invalid parameter value for redirect_uri: Non-public
domains not allowed: http://mysite.dev/index.php/oauth2/session/google
where oauth2 is my controller and session is the function where I specify
fb/google, etc
any clues/hints ? thanks