I found that jde-lib-directory-names is set to '("^lib" "^jar") by default. This doesn't work for a couple of projects I'm on that use "jar-staging-dir" as a directory name and this gets expanded in undesirable ways. So I set jde-lib-directory-names to nil and then found that this breaks jde-ant-build when using the Java invocation method. After doing some looking I came up with the solution to set jde-lib-directory-names to '("^lib$" "^jar$"). This works for everything. Perhaps the default value should be changed to be more restrictive like this, or a separate expansion variable be created for jde-ant?