Need to have gwt-dev.jar and gwt-user.jar on the classpath.
<pathelement location="${distDir}/gdx.jar"/>\r
<pathelement location="${distDir}/gdx-backend-gwt.jar"/>\r
<pathelement location="${distDir}/extensions/gdx-controllers/gdx-controllers.jar"/>\r
+ <pathelement location="${basedir}/backends/gdx-backends-gwt/libs/gwt-dev.jar"/>\r
+ <pathelement location="${basedir}/backends/gdx-backends-gwt/libs/gwt-user.jar"/>\r
</path>\r
<ant antfile="../../../build-template.xml" dir="extensions/gdx-controllers/gdx-controllers-gwt">\r
<property name="distDir" value="${distDir}/extensions/gdx-controllers"/>\r