When compiling drls the kie maven plugin uses the plugin classpath instead of the project one. This imply that it is necessary to duplicate the dependencies used by the kie project also inside the plugin declaration, as reported by this email: http://drools.46999.n3.nabble.com/rules-users-Drool-6-0-0-Final-2-question-re-kie-maven-plugin-please-td4027117.html
Fixed by https://github.com/droolsjbpm/drools/commit/b8a952e88
The problem persists with BRMS 6.0.0 ER7 (6.0.1-redhat-2). Please try to build the attached maven project (in kie-cdi-war-example, execute mvn clean install) to reproduce the problem. If you uncomment kie-maven-plugin's dependency on kie-cdi-war-model (in kie-cdi-war-example/kie-module/pom.xml), the build succeeds.
Created attachment 845018 [details] Maven project with reproducer Adding a maven project with reproducer.
The problem persists also in Drools 6.0.1-SNAPSHOT.
Fixed by https://github.com/droolsjbpm/drools/commit/fb0c4e7f0
Verified on BRMS 6.0.0 CR1.