title: Set global environment variables inside Xcode build phase run script
body: <p>I'm using Jenkins to do continuous integration builds. I have quite a few jobs that have much of the same configuration code. I'm in the midst of pulling this all out into a common script file that I'd like to run pre and post build. </p>
  
  <p>I've been unable to figure out how to set some environment variables within that script, so that both the Xcode build command, and the Jenkins build can see them.</p>
  
  <p>Does anyone know if this is possible?</p>