title: same pubspec.yaml - build for both ddc and dart2js with debug
body: <p>In current state of project I want to build both for ddc and dart2js with debug  info. Is this possible with same <code>pubspec.yaml</code>?</p>
  
  <p>Using the recommended setting for ddc, the debug mode is associated with ddc.</p>
  
  <pre><code>web:
    compiler:
      debug: dartdevc
  </code></pre>
  
  <p>While the <code>dart2js</code>build is obtained with <code>--mode=release</code> in commandline.</p>
  
  <p>Only way I find now is by un/comment out the <code>ddc</code>section from the <code>pubspec.yaml</code>.</p>