Widgetset compilation error with eclipse plugin

Vaadin 6 / 7 / 8
1

Hi Experts,

Background:
I am using Vaadin 7.6.5. Working on a product built on Vaadin and I am adding stuff to it. It all started with trying to add Checkbox to grid for a column that has boolean values. After searching for sometime I found: https://vaadin.com/directory/component/grid-renderers-collection-for-vaadin7 which seemed very apt for what I am trying to do. After I used the addon I was not able to get it working, the grid would show columns till it hit the boolean column. The boolean column and any column after that was not displayed. After further search I found that I might need to compile the widgetset. And that started my journey of endless tries and spending hours to get widgetset compiled!

The Pain:
When I hit the compile widgetset button in eclipse, I get following error in console:

Starting GWT compiler
Loading inherited module 'com.xxx.yyyy.widgetset.wwwWidgetset'
   Loading inherited module 'com.vaadin.DefaultWidgetSet'
      Loading inherited module 'com.vaadin.Vaadin'
         Loading inherited module 'com.google.gwt.user.User'
            Loading inherited module 'com.google.gwt.event.Event'
               Loading inherited module 'com.google.gwt.dom.DOM'
                  Loading inherited module 'com.google.gwt.safehtml.SafeHtml'
                     Loading inherited module 'com.google.gwt.http.HTTP'
                        Loading inherited module 'com.google.gwt.user.Timer'
                           [ERROR]
 Line 19: Unexpected exception while processing element 'source'
java.lang.NoClassDefFoundError: org/apache/tools/ant/types/ZipScanner
	at com.google.gwt.dev.resource.impl.DefaultFilters.getScanner(DefaultFilters.java:240)
	at com.google.gwt.dev.resource.impl.DefaultFilters$4.<init>(DefaultFilters.java:371)
	at com.google.gwt.dev.resource.impl.DefaultFilters.getCustomFilter(DefaultFilters.java:370)

As the error indicated the compiler is not able to find ZipScanner which seems to be from apache ant. So I added dependency in my ivy for that. After that the compile itself stopped working - I mean I did not get any errors, but it won’t compile either. The moment I removed the dependency from my ivy, I would see it compile but fail with error listed above.

I tried to remove it from ivy and put it under WEB-INF\lib - and I found the same behaviour - while it was there the compile itself would stop, if I take out it would complile but would fail with errors.

Would really appreciate any help to get the compile working and completed!!!

Thanks,
Bhartesh