title: Android Ant build using ${sdk.dir} in project.properties
body: <p>I want to use the <code>${sdk.dir}</code> variable in my project.properties file, so I can check this into version control and use the same file on different setup machines.</p>
  
  <p>My working setup looks like this:</p>
  
  <p>My <strong>project.properties</strong>:</p>
  
  <pre><code>target=android-18
  android.library.reference.1=..\\..\\..\\sdk\\extras\\android\\support\\v7\\appcompat
  android.library.reference.2=..\\..\\..\\sdk\\extras\\google\\google_play_services\\libproject\\google-play-services_lib
  </code></pre>
  
  <p>My <strong>local.properties</strong>:</p>
  
  <pre><code>sdk.dir=C:\\adt-bundle-windows-x86_64-20130917\\sdk
  </code></pre>
  
  <p>this setup compiles with ant from the command line. but when I replace the <code>..\\..\\..\\</code>with <code>${sdk.dir}</code> I get the error:</p>
  
  <p><strong>project.properties</strong> how I want it to use:</p>
  
  <pre><code>target=android-18
  android.library.reference.1=${sdk.dir}\\extras\\android\\support\\v7\\appcompat
  android.library.reference.2=${sdk.dir}\\extras\\google\\google_play_services\\libproject\\google-play-services_lib
  </code></pre>
  
  <p>results in:</p>
  
  <pre><code>BUILD FAILED
  C:\adt-bundle-windows-x86_64-20130917\sdk\tools\ant\build.xml:460:
  Failed to resolve library path:
  C:\adt-bundle-windows-x86_64-20130917\sdk\extras\android\support\v7\appcompat
  </code></pre>
  
  <p>so the variable <code>${sdk.dir}</code> is replaced correctly but somehow it cannot be resolved. Any ideas?</p>
  
  <p><strong>update Edit</strong></p>
  
  <p>Using the Variable for the proGuard setup in the same file (<code>project.properties</code>) is working fine what so ever:</p>
  
  <pre><code>proguard.config=${sdk.dir}/tools/proguard/proguard-android.txt:proguard-project.txt
  </code></pre>