title: Issue with proguardFile, null returned: 1
body: <p>Hi am trying to run "ant clean debug" command on cmd. But i am getting null returned: 1 error.</p>
  
  <pre><code>BUILD FAILED
  C:\Program Files (x86)\Android\android-sdk\tools\ant\build.xml:622: The following error    occurred while executing this line:
   C:\Program Files (x86)\Android\android-sdk\tools\ant\build.xml:658: null returned: 1
  
  
  
   &lt;aapt executable="${aapt}"
                   command="package"
                   verbose="${verbose}"
                   manifest="${out.manifest.abs.file}"
                   androidjar="${project.target.android.jar}"
                   rfolder="${gen.absolute.dir}"
                   nonConstantId="${android.library}"
                   libraryResFolderPathRefid="project.library.res.folder.path"
                   libraryPackagesRefid="project.library.packages"
                   ignoreAssets="${aapt.ignore.assets}"
                   proguardFile="${out.absolute.dir}/proguard.txt"&gt;
               &lt;res path="${out.res.absolute.dir}" /&gt;
               &lt;res path="${resource.absolute.dir}" /&gt;
           &lt;/aapt&gt;
  </code></pre>
  
  <p>the line no 658 :</p>
  
  <pre><code> proguardFile="${out.absolute.dir}/proguard.txt"&gt;
  </code></pre>
  
  <p>the line no 622 :</p>
  
  <pre><code> elseText="hasCode = false. Skipping aidl/renderscript/R.java"&gt;
  </code></pre>
  
  <p>Is their anybody their who know the solution for this issue.</p>