Upgrading a project from Grails 2.1.x to 2.2.x by running a

grails upgrade

you might run into an error of the kind:

| Error Error executing script Upgrade: Could not find matching constructor for: org.codehaus.groovy.grails.compiler.support.GrailsResourceLoader([Lorg.codehaus.groovy.grails.io.support.Resource;) (Use --stacktrace to see the full trace)

Fix is to refresh you dependencies first by running

grails refresh-dependencies.

Hope it helps.