When doing grails project with version 2.3.x and above in Intellij with version 12.x and above, there will be likely a bug that debugging in intellij doesn’t work. This relates to grails fork execution. To avoid that, in BuildConfig file, either adding :

	grails.project.fork = [
	    test: false,
	    run: false

or, if using intellij 13 and above, comment the lines started with run and test.