11 examples, 11 failures
mono$ mono ../../build/debug/rbx.exe mspec.rb 
builtin/string/append_spec.rb: .E.EFF...EE
builtin/string/capitalize_spec.rb: .F.F..E
builtin/string/casecmp_spec.rb: ..FF
builtin/string/center_spec.rb: ...FEEEE.F
builtin/string/chomp_spec.rb: .F.F.EFEEFF.E
builtin/string/chop_spec.rb: ...FF...E
builtin/string/comparison_spec.rb: E......F.EE
builtin/string/concat_spec.rb: .F.E
builtin/string/count_spec.rb: EEEEEE
builtin/string/crypt_spec.rb: EEEEEE
builtin/string/delete_spec.rb: EEEEEEEEEEE
Stacktrace:


Native stacktrace:

        mono [0x817724f]
        mono [0x807e431]
        [0xffffe440]
        [0xb6a21e07]
        [0xb6a21ce7]
        [0xb6a21338]
        [0xb6a3f358]
        [0xb6a58a9a]
        [0xb6a587c2]
        [0xb6a5796f]
        [0xb6a3b024]
        [0xb6a5796f]
        [0xb6a3f18a]
        [0xb6a5796f]
        [0xb6a20f7f]
        [0xb6a3ee0a]
        [0xb6a20c52]
        [0xb6a3ee0a]
        [0xb6a20bb8]
        [0xb6a5796f]
        [0xb6a3f138]
        [0xb6a5796f]
        [0xb6a3f0e8]
        [0xb6a3ee0a]
        [0xb6a06948]
        [0xb6a0652a]
        [0xb6a063cf]
        [0xb6a063af]
        [0xb69fe1a1]
        [0xb69fddef]
        [0xb6a3f358]
        [0xb6a58a9a]
        [0xb6a587c2]
        [0xb6a5796f]
        [0xb6a3f0e8]
        [0xb6a3ee0a]
        [0xb6a0f5d0]
        [0xb6a0f1b5]
        [0xb6a0efdc]
        [0xb6a0efbe]
        [0xb69fdb7a]
        [0xb6a253a3]
        [0xb6a3f31d]
        [0xb6a58a9a]
        [0xb6a587c2]
        [0xb6a5796f]
        [0xb6a3f0e8]
        [0xb6a3ee0a]
        [0xb6a223a0]
        [0xb6a21f82]
        [0x8937ceb]
        [0xb6a21e07]
        [0xb6a21ce7]
        [0xb6a21338]
        [0xb6a3f358]
        [0xb6a58a9a]
        [0xb6a587c2]
        [0xb6a5796f]
        [0xb6a3b024]
        [0xb6a5796f]
        [0xb6a3f18a]
        [0xb6a5796f]
        [0xb6a20f7f]
        [0xb6a3ee0a]
        [0xb6a20c52]
        [0xb6a3ee0a]
        [0xb6a20bb8]
        [0xb6a5796f]
        [0xb6a3f138]
        [0xb6a5796f]
        [0xb6a3f0e8]
        [0xb6a3ee0a]
        [0xb6a3a790]
        [0xb6a3a375]
        [0xb6a3a19c]
        [0xb6a3a17e]
        [0xb6a69813]
        [0xb6a68eda]
        [0xb6a68cc5]
        [0xb6a68c53]
        [0xb6a68c07]
        [0xb6f32ea9]
        [0xb6f32d4e]
        [0xb6f32bfa]
        [0xb6f61220]
        [0xb6f60456]
        [0xb6f6017c]
        [0xb78ad8e4]
        [0xb78ad27e]
        [0xb78ad1c4]
        mono(mono_runtime_exec_main+0x10e) [0x80d4d1e]
        mono(mono_runtime_run_main+0x173) [0x80d4fc3]
        mono(mono_main+0x6a9) [0x805ac39]
        mono [0x805a082]
        /lib/libc.so.6(__libc_start_main+0xe0) [0xb7ca6fe0]
        mono [0x8059ff1]

Debug info from gdb:

Using host libthread_db library "/lib/libthread_db.so.1".
[Thread debugging using libthread_db enabled]
[New Thread 0xb7c908f0 (LWP 5916)]
[New Thread 0xb735db90 (LWP 5919)]
[New Thread 0xb7381b90 (LWP 5918)]
0xffffe410 in __kernel_vsyscall ()
  3 Thread 0xb7381b90 (LWP 5918)  0xffffe410 in __kernel_vsyscall ()
  2 Thread 0xb735db90 (LWP 5919)  0xffffe410 in __kernel_vsyscall ()
  1 Thread 0xb7c908f0 (LWP 5916)  0xffffe410 in __kernel_vsyscall ()

Thread 3 (Thread 0xb7381b90 (LWP 5918)):
#0  0xffffe410 in __kernel_vsyscall ()
#1  0xb7df6846 in nanosleep () from /lib/libpthread.so.0
#2  0x0811f541 in collection_thread (unused=0x0) at collection.c:34
#3  0xb7def192 in start_thread () from /lib/libpthread.so.0
#4  0xb7d5402e in clone () from /lib/libc.so.6

Thread 2 (Thread 0xb735db90 (LWP 5919)):
#0  0xffffe410 in __kernel_vsyscall ()
#1  0xb7df3566 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#2  0x0811474f in timedwait_signal_poll_cond (cond=0xb785b1dc, 
    mutex=0xb785b1c4, timeout=0x0, alertable=0) at handles.c:1443
#3  0x081171bd in _wapi_handle_timedwait_signal_handle (handle=0x404, 
    timeout=0x0, alertable=0) at handles.c:1523
#4  0x0811722c in _wapi_handle_wait_signal_handle (handle=0x404, alertable=0)
    at handles.c:1483
#5  0x081236da in WaitForSingleObjectEx (handle=0x404, timeout=4294967295, 
    alertable=0) at wait.c:200
#6  0x080b4caa in finalizer_thread (unused=0x0) at gc.c:845
#7  0x080b1724 in start_wrapper (data=0x8255638) at threads.c:550
#8  0x0811edd2 in thread_start_routine (args=0xb77073c0) at threads.c:264
#9  0x08132135 in GC_start_routine (arg=0x22f40) at pthread_support.c:1369
#10 0xb7def192 in start_thread () from /lib/libpthread.so.0
#11 0xb7d5402e in clone () from /lib/libc.so.6

Thread 1 (Thread 0xb7c908f0 (LWP 5916)):
#0  0xffffe410 in __kernel_vsyscall ()
#1  0xb7d4d591 in select () from /lib/libc.so.6
#2  0xb7e65c49 in g_spawn_sync () from /usr/lib/libglib-2.0.so.0
#3  0xb7e6603c in g_spawn_command_line_sync () from /usr/lib/libglib-2.0.so.0
#4  0x081772e1 in mono_handle_native_sigsegv (signal=11, ctx=0xb7b60d0c)
    at mini-exceptions.c:1061
#5  0x0807e431 in mono_arch_handle_altstack_exception (sigctx=0xb7b60d0c, 
    fault_addr=0x0, stack_ovf=0) at exceptions-x86.c:854
#6  <signal handler called>
#7  0x08eb5be0 in ?? ()
#8  0x000b5750 in ?? ()
#9  0x0004ed20 in ?? ()
#10 0x000c29c0 in ?? ()
#11 0x00000003 in ?? ()
#12 0x000b5750 in ?? ()
#13 0x000be2e8 in ?? ()
#14 0x0000000a in ?? ()
#15 0xbfc30f14 in ?? ()
#16 0xb6a21e07 in ?? ()
#17 0x00333ac0 in ?? ()
#18 0x00218510 in ?? ()
#19 0x000c02d0 in ?? ()
#20 0x0004ed20 in ?? ()
#21 0x000c29c0 in ?? ()
#22 0xbfc30f50 in ?? ()
#23 0xb6a21ce7 in ?? ()
#24 0x00218510 in ?? ()
#25 0x000c02d0 in ?? ()
#26 0x0004ed20 in ?? ()
#27 0x000c29c0 in ?? ()
#28 0x00c30f3c in ?? ()
#29 0x000c29c0 in ?? ()
#30 0x00218510 in ?? ()
#31 0x0004ed20 in ?? ()
#32 0x000c02d0 in ?? ()
#33 0x00000000 in ?? ()
#0  0xffffe410 in __kernel_vsyscall ()


=================================================================
Got a SIGSEGV while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries 
used by your application.
=================================================================