This is something weird, I have been spending the last few days trying to get Google+ sign in button working, I also tried Persona (from Mozilla) just so that users don't have to remember another user/pw combination.
I have been running into this issue, cURL is not able to resolve the google account page. Here is the error:
http://hastebin.com/baxasagoci.cmake
And here is the page from the same vps:
http://snapr.pw/i/d77e76edd2.png
Now the weirdest part is that it is only happening on this vps. I tried on another vps from the same provider in the Netherlands, I also tried on my Rasperry Pi in Rotterdam (PCExtreme, also NL) and both are working fine. This is the only vps the problem occurs. Both servers have the same /etc/resolv.conf. I tried the most recent source from Github but also a older one from a tutorial found online. Both produce the same error. And it isn't google's fault because Persona is also giving me problems.
To be clear, I don't really need this to be fixed, I just want to know why this is happening.