While running SPECjbb2005 with G1 I experienced the following crash:
--------------------------------
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/home/jc234399/ws/hs-gc2/hotspot/src/share/vm/utilities/growableArray.hpp:186), pid=13408, tid=5
# Error: assert(0 <= i && i < _len,"illegal index")
#
# JRE version: 7.0-b54
# Java VM: OpenJDK Server VM (15.0-b04-internal-jvmg mixed mode solaris-x86 )
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
#

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

Current thread (0x080a7c00): GCTaskThread [stack: 0x00000000,0x00000000] [id=5]
....

Other Threads:
  0x0a288000 VMThread [stack: 0xfa6bb000,0xfa6fb000] [id=11]
  0x0a2b8400 WatcherThread [stack: 0x1b12d000,0x1b16d000] [id=19]

=>0x080a7c00 (exited) GCTaskThread [stack: 0x00000000,0x00000000] [id=5]

VM state:at safepoint (normal execution)

VM Mutex/Monitor currently owned by a thread: ([mutex/lock_event])
[0x08099f10] Threads_lock - owner thread: 0x0a288000
[0x0809a5a0] Heap_lock - owner thread: 0x0809b400

Heap
            0 space 1024K, 34% used [0x1ba00000, 0x1ba587a0, 0x1bb00000)
          F 0 space 1024K, 0% used [0x1bb00000, 0x1bb00000, 0x1bc00000)
          F 0 space 1024K, 0% used [0x1bc00000, 0x1bc00000, 0x1bd00000)
          F 0 space 1024K, 0% used [0x1bd00000, 0x1bd00000, 0x1be00000)
....
          F 0 space 1024K, 0% used [0xf5500000, 0xf5500000, 0xf5600000)
    A SU F 1 space 1024K, 0% used [0xf5600000, 0xf5600000, 0xf5700000)
    A F 1 space 1024K, 0% used [0xf5700000, 0xf5700000, 0xf5800000)
    CS Y 0 space 1024K, 100% used [0xf5800000, 0xf5900000, 0xf5900000)
    CS Y 0 space 1024K, 100% used [0xf5900000, 0xf5a00000, 0xf5a00000)
    CS Y 0 space 1024K, 100% used [0xf5a00000, 0xf5b00000, 0xf5b00000)
    CS Y 0 space 1024K, 100% used [0xf5b00000, 0xf5c00000, 0xf5c00000)
    CS Y 0 space 1024K, 100% used [0xf5c00000, 0xf5d00000, 0xf5d00000)
    CS Y 0 space 1024K, 100% used [0xf5d00000, 0xf5e00000, 0xf5e00000)
    CS Y 0 space 1024K, 100% used [0xf5e00000, 0xf5f00000, 0xf5f00000)
    CS Y 0 space 1024K, 100% used [0xf5f00000, 0xf6000000, 0xf6000000)
    CS Y 0 space 1024K, 100% used [0xf6000000, 0xf6100000, 0xf6100000)
    CS Y 0 space 1024K, 100% used [0xf6100000, 0xf6200000, 0xf6200000)
    CS Y 0 space 1024K, 100% used [0xf6200000, 0xf6300000, 0xf6300000)
    CS Y 0 space 1024K, 99% used [0xf6300000, 0xf63ffcb0, 0xf6400000)
    CS Y 0 space 1024K, 100% used [0xf6400000, 0xf6500000, 0xf6500000)
    CS Y 0 space 1024K, 100% used [0xf6500000, 0xf6600000, 0xf6600000)

VM Arguments:
jvm_args: -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -Xmx3500m -Xms3500m -XX:+PrintGCDetails -XX:+PrintGCTimeStamps
java_command: spec.jbb.JBBmain -propfile SPECjbb.props
Launcher Type: SUN_STANDARD

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I was running SPECjbb2005 with a 32 bit debug JVM.