Specifically I'm trying to combine lesscss-resources with smartsprites-csssprites-resources
beckje01/smartsprites-csssprites-resources#7
The issue isn't limited to that plugin though, I created a new grails app, installed the lesscss plugin, and wrote my own debug resourceMapper and set it to run in the MUTATE phase
When defaultIncludes was set to "/*.css" it does not pick up any less generated files
When defaultIncludes was set to "/*.less" it picked up a resource with the url "/css/fancy_less.css"