The Ant verbose option can give you the information about what Ant is doing. you can turn on the verbose flag to debug the ant script:

How to do? If you use Ant command line, you can execute ant with -verbose flag:

ant -verbose  OR  ant -v

This will produce output that starts like the following:

Apache Ant version 1.7.0 compiled on December 13 2006
Buildfile: build.xml
Detected Java version: 1.6 in: C:\CommonProgram\Java\jdk1.6.0_25\jre
Detected OS: Windows 7
parsing buildfile D:\WS\build.xml with URI = file:/D:/WS/build.xml
Project base dir set to: D:\WS
[] Could not load definitions from resource org/apache/tools/ant/antlib.xml. It could not be
Property “” has not been set
Property “” has not been set

If you use eclipse, you can set eclipse External Tools Configuration parameter with verbose flag. Please see the screenshot below: