It works with Spock v0.7-groovy-2.0, but it doesn't work with Spock v1.0-groovy-2.0-SNAPSHOT.
The root cause is that the IGlobalExtension interface changed and it now has start() and stop() methods, which the v0.7 version did not have, and so an AbstractMethodError: null is thrown:
java.lang.AbstractMethodError: null
at org.spockframework.runtime.GlobalExtensionRegistry.startGlobalExtensions(GlobalExtensionRegistry.java:105)
at org.spockframework.runtime.RunContext.start(RunContext.java:63)
at org.spockframework.runtime.RunContext.get(RunContext.java:165)
at org.spockframework.runtime.Sputnik.runExtensionsIfNecessary(Sputnik.java:88)
at org.spockframework.runtime.Sputnik.run(Sputnik.java:61)
at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:264)
at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:153)
at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:124)
Because of this, we cannot use the most recent features in Spock, since v0.7 is more than 2 years old.
Medium 