unable to run any tests, all resulted in a ClassNotFoundException:

Caused by: java.lang.ClassNotFoundException: org.jboss.arquillian.junit.standalone.SpockStandaloneExtension

Happens every time the runner tries to initialize services. The SpockStandaloneExtension class is on the classpath, but looks like it is in a different package: org.jboss.arquillian.spock.standalone.SpockStandaloneExtension