Importing plugin classes into Grails scripts

Classes from plugin src folder are not available to Grails scripts or plugin scripts itself. They can be compiled and manually loaded, but will be only available for applications or tests launched from script - not to script itself.
However it is easy to work around this issue if it is your plugin or you can rebuild it. It is only needed to compile classes into lib when packing plugin, after that all libs are loaded when running script.
For example this can be done by adding next snippet into _Events.groovy file of the plugin:

eventPackagePluginStart = {
  compile()
  ant.jar ( destfile : 'lib/pluginlibs.jar' , basedir : 'target/classes', includes:"com/myplugin/**")
}