The following test failure was spotted in the 2017-08-08 JDK10-hs nightly:

compiler/codecache/stress/RandomAllocationTest.java
    Test failed the following assertion:

    Internal Error (<path>\\hotspot\\src\\share\\vm\\gc/g1/g1ConcurrentMark.inline.hpp:50), pid=6908, tid=6936
    assert(obj->is_oop(true )) failed: Address 0x00000003c2eb11a8 to mark is not an oop

    on Win Server 2012 64-bit Server VM.

    Here's a snippet of the stack trace:

    V [jvm.dll+0xc05c1f] VMError::report_and_die+0x3f;; ?report_and_die@VMError@@SAXPEAVThread@@IPEAEPEAX2@Z+0x3f
    V [jvm.dll+0xa48cec] topLevelExceptionFilter+0x47c;; ?topLevelExceptionFilter@@YAJPEAU_EXCEPTION_POINTERS@@@Z+0x47c
    V [jvm.dll+0xc3e6f8] `thread_native_entry'::`1'::filt$0+0x18;; ?filt$0@?0??thread_native_entry@@YAIPEAVThread@@@Z@4HA+0x18
    C [msvcr120.dll+0x6f2cb]
    V [jvm.dll+0xc3df52] __GSHandlerCheck_SEH+0x76;; __GSHandlerCheck_SEH+0x76
    C [ntdll.dll+0x933fd]
    C [ntdll.dll+0x54847]
    C [ntdll.dll+0x9258a]
    V [jvm.dll+0xa389f9] os::is_first_C_frame+0x29;; ?is_first_C_frame@os@@SA_NPEAVframe@@@Z+0x29