assert((*t)->is_oop_or_null()) failed: Expected an oop or NULL

Testing G1 as default.

# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/opt/jprt/T/P1/075059.sjohanss/s/hotspot/src/share/vm/utilities/taskqueue.hpp:334), pid=3078, tid=2742713232
# assert((*t)->is_oop_or_null()) failed: Expected an oop or NULL at 0xa9200000
#
# JRE version: Java(TM) SE Runtime Environment (9.0) (build 1.9.0-internal-fastdebug-20150330075059.sjohanss.g1-server-defaul-b00)
# Java VM: Java HotSpot(TM) Server VM (1.9.0-internal-fastdebug-20150330075059.sjohanss.g1-server-defaul-b00 compiled mode linux-x86 )
# Failed to write core dump. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again
#
# If you would like to submit a bug report, please visit:
# http://bugreport.java.com/bugreport/crash.jsp
#

--------------- T H R E A D ---------------

Current thread (0xa363dc00): VMThread [stack: 0xa3727000,0xa37a8000] [id=3099]

Stack: [0xa3727000,0xa37a8000], sp=0xa37a6ad0, free space=510k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0x104cc98] VMError::report_and_die()+0x198
V [libjvm.so+0x6d8df6] report_vm_error(char const*, int, char const*, char const*)+0x76
V [libjvm.so+0x680714] ConcurrentMark::verify_no_cset_oops(bool, bool, bool, bool)+0x844
V [libjvm.so+0x7f0bf5] G1CollectedHeap::do_collection_pause_at_safepoint(double)+0xc65
V [libjvm.so+0x107c540] VM_G1IncCollectionPause::doit()+0xc0
V [libjvm.so+0x107a727] VM_Operation::evaluate()+0x97
V [libjvm.so+0x1077c35] VMThread::evaluate_operation(VM_Operation*)+0x145
V [libjvm.so+0x1078585] VMThread::loop()+0x4e5
V [libjvm.so+0x10787cc] VMThread::run()+0xcc
V [libjvm.so+0xd90af0] java_start(Thread*)+0x100
C [libpthread.so.0+0x5832]

VM_Operation (0xa285c878): G1IncCollectionPause, mode: safepoint, requested by thread 0xa290cc00