title: Failure: build failed with an exception a problem occured configuring root project 'android'
body: <p>I'm building a hybrid app using ionic framework.
  I did installed npm,cordova, ionic and android sdk.
  also I have set the environment variables.
  I was able to run following commands </p>
  
  <ol>
  <li>ionic start todo blank </li>
  <li>cd todo</li>
  <li>ionic platform add android</li>
  </ol>
  
  <p>but when I run
  ionic build android
  The build fails.</p>
  
  <p>BUILD FAILED</p>
  
  <p>Total time: 29.551 secs
  FAILURE: Build failed with an exception.</p>
  
  <ul>
  <li><p>What went wrong:
  A problem occurred configuring root project 'android'.</p>
  
  <blockquote>
    <p>java.lang.NullPointerException (no error message)</p>
  </blockquote></li>
  <li><p>Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
  Error: cmd: Command failed with exit code 1 Error output:
  FAILURE: Build failed with an exception.</p></li>
  <li><p>What went wrong:
  A problem occurred configuring root project 'android'.</p>
  
  <blockquote>
    <p>java.lang.NullPointerException (no error message)</p>
  </blockquote></li>
  <li><p>Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.</p></li>
  </ul>