An entry from my nightly analysis report:

New vm.heapdump failures (from 2008.10.13)
    heapdump/JMapPermCore
        This test failed due to SIGSEGV on Solaris SPARC Server VM
        (machine sys-ldom1-06). The hs_err file shows the crash in "C
        [libc.so.1+0xc5c20]". pstack output shows a litte more:

            _lwp_kill (6, 0, ff172e90, ff128bd0, ffffffff, 6) + 8
            abort (ffbfe238, 1, fdace53c, ad314, ff1712d8, 0) + 110
            __1cCosFabort6Fb_v_ (ffbfe238, fee3b6cc, fee3b6cc, 7e254, 1, fe9c17db) + 168
            __1cHVMErrorOreport_and_die6M_v_ (99000, 0, fee3b6cc, 99000, 58c00,
1) + c10
            JVM_handle_solaris_signal (b, 0, ffbfe5e0, 1, 0, 4) + cc4
            __sighndlr (b, ffbfe898, ffbfe5e0, fdac572c, 0, 1) + c
            call_user_handler (b, ffbffeff, c, 0, ff162a00, ffbfe5e0) + 3b8
            __lwp_wait (2, ffbfe9dc, 0, 0, ff2342f0, 0) + 8
            _thrp_join (2, 0, ffbfeaa0, 1, ffbfe9dc, ff173700) + 34
            thr_join (2, 0, ffbfeaa0, ffbfeb18, 0, 0) + 10

        I suspect we crashed trying to report a VM error. See the
        JMapHeapCore SIGSEGV crash below.

        Update: Very similar failure in 2008.11.01 nightly on Solaris
            SPARC Server VM (machine sys-ldom1-02).

        Update: Very similar failure in 2008.11.21 nightly on Solaris
            SPARC Server VM (machine sys-ldom1-01).
There were crashes in G1 PIT on solaris-amd64, solaris-i586, solaris-sparc/v9 and linux-i586, which look like this one:

http://vmsqe.russia.sun.com/execution/results/JDK7/PROMOTION/VM/b99/G1/new_unknown_failures.html

Below are stack dumps:

solaris-sparc and -sparcv9:
C [libc.so.1+0xda0c4];; __lwp_wait+0x8
C [libc.so.1+0xd25ec];; _thrp_join+0x40
C [libc.so.1+0xd278c];; thr_join+0x18
C [libjli.so+0x7084];; ContinueInNewThread0+0x38
C [libjli.so+0x1bd0];; JLI_Launch+0x618
C [java+0x9e4]

solaris-amd64:
C [libc.so.1+0xdcbba] _lwp_self+0x1a;; __lwp_wait+0xa
C [libc.so.1+0xd3cbe] _pthread_exit+0x4e;; _thrp_join+0x3e
C [libc.so.1+0xd3e6e] thr_join+0xe;; thr_join+0xe
C [libjli.so+0xb644] JLI_ReportExceptionDescription+0x8e4;; ContinueInNewThread0+0x44
C [libjli.so+0x4319] JLI_Launch+0x1639
C [java+0x8e2] main+0x72
C [java+0x71c] _PROCEDURE_LINKAGE_TABLE_+0xc4

solaris-i586:
C [libc.so.1+0xaab75];; __lwp_wait+0x15
C [libc.so.1+0xa4436];; _thrp_join+0x5a
C [libc.so.1+0xa4578] thr_join+0x20;; thr_join+0x20
C [libjli.so+0x8eb4];; ContinueInNewThread0+0x54
C [libjli.so+0x2986] JLI_Launch+0x16b6
C [java+0x809] main+0x6d
C [java+0x70d] _start+0x7d

linux-i586:
C [+0x40e] __kernel_vsyscall+0xe
C 0x00006e96
C [libjli.so+0x55ea];; ContinueInNewThread0+0xaa
C [libjli.so+0x4469] JLI_Launch+0xa59;; JLI_Launch+0xa59
C [java+0x56d];; main+0xad
C [libc.so.6+0x1589c] __libc_start_main+0xdc