The project assumes that jar files are available in the Ivy cache. Run 'ant' to package the plugin and this will resolved dependencies. STS: - you'll need to create the IVY_CACHE variable to point at your ~/.ivy2/cache folder so the classpath jars resolve - if you have the Spring Security distro you can set the SPRING_SECURITY_SOURCE variable to point at the dist folder so the source path resolves correctly for the classpath jars