Bootcycle build appears to fail with:
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[snip]
Making /hudson/jobs/jdk9-jdk-build-all/workspace/build/linux-x86_64-normal-server-release/bootcycle-build/hotspot/linux_amd64_compiler2/product/../generated/sa-jdi.jar
warning: [options] bootstrap class path not set in conjunction with -source 1.6
/hudson/jobs/jdk9-jdk-build-all/workspace/hotspot/agent/src/share/classes/sun/jvm/hotspot/jdi/ConcreteMethodImpl.java:40: error: ConcreteMethodImpl is not abstract and does not override abstract method isDefault() in Method
public class ConcreteMethodImpl extends MethodImpl {
       ^
/hudson/jobs/jdk9-jdk-build-all/workspace/hotspot/agent/src/share/classes/sun/jvm/hotspot/jdi/InterfaceTypeImpl.java:44: error: InterfaceTypeImpl is not abstract and does not override abstract method invokeMethod(ThreadReference,Method,List<? extends Value>,int) in InterfaceType
public class InterfaceTypeImpl extends ReferenceTypeImpl
       ^
/hudson/jobs/jdk9-jdk-build-all/workspace/hotspot/agent/src/share/classes/sun/jvm/hotspot/jdi/NonConcreteMethodImpl.java:41: error: NonConcreteMethodImpl is not abstract and does not override abstract method isDefault() in Method
public class NonConcreteMethodImpl extends MethodImpl {
       ^
Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
3 errors
1 warning
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This may be caused by the fix for JDK-8031195/JDK-8042091:
http://hg.openjdk.java.net/jdk9/dev/jdk/rev/4e7f3aac979b