I tried to package my app as a grails plugin and it seemed working though I got a error message "error: error reading C:\grails\lib\readme.txt; error in opening zip file" while packaging it. Then I installed my packaged plugin into a fresh grails app, so good so far. However, when I tried to grails compile the new app, it failed and complained that the Java classes in the plugins/someplugin-0.1/src/java can not be resolved. Please download the following app and run grails compile there to reproduce the errors. http://www.dcs.shef.ac.uk/~hsun/downloads/CowDemo.zip