HowTo: Check for JUnit in $ANT_HOME/lib
One of the most common problems with my sample apps is that developers (when compiling from source) forget to put junit.jar in their $ANT_HOME/lib directory. I put it in the README, but I guess no one reads that sucker. So now I have a new strategy - stop the build if it's not there:
<!-- Check that junit.jar is in $ANT_HOME/lib -->
<available classname="junit.framework.TestCase"
property="junit.present"/>
<fail unless="junit.present"
message="Please copy junit.jar into ${env.ANT_HOME}/lib"/>