title: Xcode workspace reference project by environment variable
body: <p>I need to reference a project in a Xcode workspace by an environment variable. An Xcode workspace file might look like this: </p>
  
  <pre><code>&lt;Workspace
     version = "1.0"&gt;
     &lt;FileRef
        location = "group:../../Some/Dir/SomeLibrary.xcodeproj"&gt;
     &lt;/FileRef&gt;
     &lt;FileRef
        location = "group:SomeApp/SomeApp.xcodeproj"&gt;
     &lt;/FileRef&gt;
  &lt;/Workspace&gt;
  </code></pre>
  
  <p>I want the SomeLibrary project to be referenced by an environment variable, so that the workspace file and projects can be used in different developer environments (the lib project is shared between several different projects). Any ideas on how to do this? Is the XML-format documented somewhere?</p>
  
  <p>Thanks! :)</p>