Node.js "passport-google-oauth2" delivers "failed to fetch user profile" error in Express application

I just fortunately found a similar issue at jaredhanson/passport-google-oauth, which gave me the idea to go to the Google's project console and simply enable the Google+ API, which was "turned off" (oh me!!, naive developer of his first application based on Google+). That was the root of the problem. I tried again and the oauth2 started receiving profiles correctly.

The scope you are using is deprecated now :

passport.authenticate('google', { successRedirect: '/',scope:
  [ 'https://www.googleapis.com/auth/userinfo.email']})
);

Instead, we must use this one:

passport.authenticate('google', { successRedirect: '/',scope:
  ['email']
}));

You can also get the profile scope:

passport.authenticate('google', { successRedirect: '/',scope:
  [ 'email', 'profile' ]
}));