Mysterious crash (on ARM)

[djs55]

Program received signal SIGILL, Illegal instruction.
[Switching to Thread 0xb6c3f460 (LWP 14927)]
0xb6d22358 in ?? ()
(gdb) 
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(gdb) bt
#0  0xb6d22358 in ?? ()
#1  0x0019c0e0 in caml_start_program ()
#2  0x0019a54a in caml_callback ()
#3  0x00000000 in ?? ()
(gdb) thread apply all bt

Thread 5 (Thread 0xb50ff460 (LWP 14954)):
#0  0xb6fb961e in read () at ../sysdeps/unix/syscall-template.S:81
#1  0x00195042 in caml_do_read ()
#2  0x0019524e in caml_input_scan_line ()
#3  0x00195ad8 in caml_ml_input_scan_line ()
#4  0x0019c098 in caml_c_call ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)

Thread 4 (Thread 0xb5c3f460 (LWP 14929)):
#0  0xb6fb961e in read () at ../sysdeps/unix/syscall-template.S:81
#1  0x00195042 in caml_do_read ()
#2  0x0019524e in caml_input_scan_line ()
#3  0x00195ad8 in caml_ml_input_scan_line ()
#4  0x0019c098 in caml_c_call ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)

Thread 3 (Thread 0xb643f460 (LWP 14928)):
#0  0xb6edf0f2 in select () at ../sysdeps/unix/syscall-template.S:81
#1  0x0018b502 in caml_thread_tick ()
#2  0xb6fb3fbc in start_thread (arg=0xb643f460) at pthread_create.c:314
#3  0xb6ee398c in ?? () at ../ports/sysdeps/unix/sysv/linux/arm/nptl/../clone.S:92 from /lib/arm-linux-gnueabihf/libc.so.6
Backtrace stopped: previous frame identical to this frame (corrupt stack?)

Thread 2 (Thread 0xb6c3f460 (LWP 14927)):
#0  0xb6d22358 in ?? ()
#1  0x0019c0e0 in caml_start_program ()
#2  0x0019a54a in caml_callback ()
#3  0x00000000 in ?? ()

Thread 1 (Thread 0xb6ff8000 (LWP 14924)):
#0  0xb6edf0f2 in select () at ../sysdeps/unix/syscall-template.S:81
#1  0x0018d89e in unix_select ()
#2  0x0019c098 in caml_c_call ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
(gdb)