title: Failure to setup GLXContext
body: <p>I am trying to setup window-less OpenGL rendering. I am following <a href="https://sidvind.com/wiki/Opengl/windowless" rel="nofollow noreferrer">these instructions</a> for "Offscreen rendering only."</p>
  
  <p>The code fails right here:</p>
  
  <pre><code>/* get framebuffer configs, any is usable (might want to add proper attribs) */
  if ( !(fbc = glXChooseFBConfig(dpy, DefaultScreen(dpy), visual_attribs, &amp;fbcount) ) ){
      fprintf(stderr, "Failed to get FBConfig\n");
      exit(1);
  }
  </code></pre>
  
  <p><code>glXChooseFBConfig</code> fails to set or retrieve a FBConfig. </p>
  
  <p>I should mention that I am ssh'ing into an AWS ubuntu 12.04 machine without the <code>-X</code> option (should I?) I also have a VNC server running that I'm tunneling into through ssh. I have tried the accepted solution to <a href="https://stackoverflow.com/questions/19393333/glxchoosefbconfig-returns-null">this question</a>, namely changing the <code>DISPLAY</code> env variable, but that still doesn't work:</p>
  
  <pre><code>$ export DISPLAY=:0
  $ ./testglXContext
  No protocol specified
  No protocol specified
  No protocol specified
  No protocol specified
  Failed to open display
  $ 
  </code></pre>
  
  <p>What should I do?</p>