title: .xcconfig? How to set environment variables
body: <p>I'm new to Xcode.</p>
  
  <p>I spent the last two days trying to figure out how to test my app on my iPhone which accesses a web service. On the simulator I can use a hard-coded 'localhost' variable, but I don't want to hardcode all the configuration settings.</p>
  
  <p>I'm using Swift + Xcode 6 but I think this is the same process as Xcode 5.</p>
  
  <p>I looked through lots of articles and I think I'm supposed to use .xcconfig, but it's very unclear.</p>
  
  <p>For example, I created a <code>Environment.xcconfig</code> file. I populated it with </p>
  
  <pre><code>API_BASE_URL = "http://localhost:4000/api/v1"
  </code></pre>
  
  <p>I then went into Project -> Info and set the Debug configuration file to <code>Environment</code>. </p>
  
  <p>I then tried to access the variable in code via <code>${API_BASE_URL}</code> but I get <code>Use of unresolved identifier 'API_BASE_URL'</code>. </p>
  
  <p>This is extremely frustrating. Any ideas?</p>