Running ant build gives “package org.junit does not exist”

Question

When I use a Java IDE to build projects (e.g. NetBeans) that have JUnit tests, they compile fine, but when I try to use ant outside of the IDE to run the build script, I get

Answer 1

The problem was that in the IDE, it set the classpath correctly to include the .jar for JUnit. Running ant outside the IDE, the classpath was different, thus the error. The fix was to put the JUnit .jar in the folder "C:\Program Files\Java\jre6\lib\ext" so it would always be found outside of any IDE.