title: Android.mk debug output
body: <p>I am building Froyo, is it possible that during building, make/python can output the file and the command it is calling right now.</p>
  
  <p>For example, in one of the Android.mk, there is a line, says,
  echo build success.
  On the monitor it will show "build success", 
  what I want is that in addition, it shows 
  "Android.mk line 20: echo build success".</p>
  
  <p>Is it possible?</p>