title: What do setting do I use for xcode-select -switch?
body: <p>I'm trying to install octave on macos mountain lion via the following:</p>
  
  <pre><code>sudo port install octave
  </code></pre>
  
  <p>However, the result of this command is always the following:</p>
  
  <pre><code>Error: 
  Error: No valid Xcode installation is properly selected.
  Error: Please use xcode-select to select an Xcode installation:
  Error:     sudo xcode-select -switch /Applications/Xcode.app/Contents/Developer # version 4.4
  Error: 
  </code></pre>
  
  <p>I've tried the suggested <code>sudo xcode-select -switch</code> command to no avail. The same error always occurs. Any ideas how to resolve this problem?</p>