"Got signal before environment was installed on our thread"

[Dima Pasechnik]

Hi Daniel,
Thanks for the message. The scenario you talk about only happens if GC
is a shared library, right?

I've rebuilt GC disabling shared libs, and ECL doing static linking to GC.
And I still get very similar segfaults:

;;; ECL C Backtrace
;;;    0 ecl_internal_error (0x87d79b375)
;;;    1 init_unixint (0x87d7c17e0)
;;;    2 init_unixint (0x87d7c1582)
;;;    3 pthread_sigmask (0x80103779d)
;;;    4 pthread_getspecific (0x801036d6f)
;;;    5 unknown (0x7ffffffff193)
;;;    6 GC_push_current_stack (0x87d7ef7c3)
;;;    7 GC_with_callee_saves_pushed (0x87d7f7360)
;;;    8 GC_push_roots (0x87d7ef9c2)
;;;    9 GC_mark_some (0x87d7ec97c)
;;;   10 GC_stopped_mark (0x87d7e6b7a)
;;;   11 GC_try_to_collect_inner (0x87d7e6a75)
;;;   12 GC_init (0x87d7f08ea)
;;;   13 init_alloc (0x87d7d5669)
;;;   14 cl_boot (0x87d69f66b)
...

And a very similar picture on the develop branch of ECL - although
I had to change our code, as  in particular
ECL_OPT_TRAP_SIGCHLD is gone...

So, what can it be? Some signals issue?

Thanks,
Dima

On Fri, Sep 1, 2017 at 7:38 AM, Daniel Kochmański <daniel at turtleware.eu> wrote:
> Hey Dima,
>
> this looks like the issue with having GC initialized before ECL kicks in.
> See https://gitlab.com/embeddable-common-lisp/ecl/issues/371 for a
> discussion about this problem. Basically some other component already called
> GC_init and ECL calls it once more. It's arguably not a bug.
>
> Best regards,
>
> Daniel
>
>
> On 31.08.2017 15:29, Dima Pasechnik wrote:
>>
>> Dear all,
>>
>> I'm struggling to understand strange segfaults coming from
>> ECL(+Maxima) on FreeBSD embedded into Python; they typically look as
>> follows:
>>
>> Got signal before environment was installed on our thread
>>    [2: No such file or directory]
>>
>> ;;; ECL C Backtrace
>> ;;;    0 ecl_internal_error (0x87d790765)
>> ;;;    1 init_unixint (0x87d7b6bd0)
>> ;;;    2 init_unixint (0x87d7b6972)
>> ;;;    3 pthread_sigmask (0x80103779d)
>> ;;;    4 pthread_getspecific (0x801036d6f)
>> ;;;    5 unknown (0x7ffffffff193)
>> ;;;    6 GC_push_all_stacks (0x87db1ea2c)
>> ;;;    7 GC_mark_some (0x87db12eec)
>> ;;;    8 GC_stopped_mark (0x87db09baa)
>> ;;;    9 GC_try_to_collect_inner (0x87db09a75)
>> ;;;   10 GC_init (0x87db16f4f)
>> ;;;   11 init_alloc (0x87d7caa59)
>> ;;;   12 cl_boot (0x87d694a5b)
>> ;;;   13 initecl (0x87d218340)
>> ;;;   14 initecl (0x87d20a43f)
>> ;;;   15 initecl (0x87d207e28)
>> ;;;   16 _PyImport_LoadDynamicModule (0x800b3ed1c)
>> ;;;   17 PyImport_AppendInittab (0x800b3d71f)
>> ;;;   18 PyImport_AppendInittab (0x800b3d1a8)
>> ;;;   19 PyImport_ImportModuleLevel (0x800b3c2ce)
>> ;;;   20 _PyBuiltin_Init (0x800b162d7)
>> ;;;   21 PyObject_Call (0x800a7d3e3)
>> ;;;   22 PyEval_EvalFrameEx (0x800b2121c)
>> ;;;   23 PyEval_EvalCodeEx (0x800b1b5d4)
>> ;;;   24 PyEval_EvalCode (0x800b1ad96)
>> ;;;   25 PyImport_ExecCodeModuleEx (0x800b3ad11)
>> ;;;   26 PyImport_AppendInittab (0x800b3ddb8)
>> ;;;   27 PyImport_AppendInittab (0x800b3d71f)
>> ;;;   28 PyImport_AppendInittab (0x800b3d1a8)
>> ;;;   29 PyImport_ImportModuleLevel (0x800b3c2ce)
>> ;;;   30 _PyBuiltin_Init (0x800b162d7)
>> ;;;   31 PyEval_EvalFrameEx (0x800b22dd1)
>> Segmentation fault (core dumped)
>>
>> It looks as if ECL (version 16.1.2) is being called before an
>> initialisation is complete, but it it possible to say more without a
>> debugger?
>>
>> More details: is is on FreeBSD 11.0, clang 3.8.0, GC version 7.6.0
>> with libatomic_ops version 7.4.6.
>> And only reproducible on FreeBSD.
>>
>> ECL is built with --disable-threads; GC is built with or without
>> threads---result is still the same.
>> (so it's unclear to me where pthread_* calls in the trace
>> come from).
>>
>> Thanks,
>> Dima
>>
>> PS. the segfault is at the bottom of
>> https://trac.sagemath.org/ticket/22679#comment:87
>>
>