Re: boehm-gc troubles with 2.0.10 on NetBSD/i386

[Mark H Weaver]

Greg Troxel <address@hidden> writes:

> Mark H Weaver <address@hidden> writes:
>
>>> Program received signal SIGSEGV, Segmentation fault.
>>> [Switching to LWP 1]
>>> 0xbba868ae in GC_find_limit_with_bound () from /usr/pkg/lib/libgc.so.1
>>> (gdb) bt
>>> #0  0xbba868ae in GC_find_limit_with_bound () from /usr/pkg/lib/libgc.so.1
>>> #1  0xbba8696e in GC_find_limit () from /usr/pkg/lib/libgc.so.1
>>> #2  0xbba8699d in GC_init_netbsd_elf () from /usr/pkg/lib/libgc.so.1
>>> #3  0xbba85b3f in GC_init () from /usr/pkg/lib/libgc.so.1
>>> #4  0xbbaf9748 in scm_storage_prehistory () from .libs/libguile-2.0.so.29
>>> #5  0xbbb0abaf in scm_i_init_guile () from .libs/libguile-2.0.so.29
>>> #6  0xbbb6712c in scm_i_init_thread_for_guile () from 
>>> .libs/libguile-2.0.so.29
>>> #7  0xbbb67347 in with_guile_and_parent () from .libs/libguile-2.0.so.29
>>> #8  0xbba85767 in GC_call_with_stack_base () from /usr/pkg/lib/libgc.so.1
>>> #9  0xbbb67529 in scm_with_guile () from .libs/libguile-2.0.so.29
>>> #10 0xbbb0ab67 in scm_boot_guile () from .libs/libguile-2.0.so.29
>>> #11 0x08048ce9 in main ()
>>
>> My guess is that this SIGSEGV is probably intentional, perhaps the
>> method used by GC on NetBSD to determine the bounds of the stack or some
>> other data area.  I would try continuing and seeing what happens next.
>> GC may also use some other signals for its own purposes.
>
> continuing leads to the program exiting.  I should build libgc with
> debugging...

In an earlier message, you wrote that guild prints the following when
run normally:

> /usr/pkgsrc/wip/guile2/work/guile-2.0.10/libguile > ../meta/uninstalled-env 
> ../meta/guild
> 0xbbbe12d4 is not a GC visible pointer location
> GC_is_visible test failed
> Abort trap (core dumped)

Does this not happen when running it within GDB?

It would be good to try building with -g and -Og or -O0, and perhaps
also installing a more recent version of GDB.

While helping someone working on getting Guile 2 into FreeBSD ports, I
learned that FreeBSD includes a very old version of GDB, presumably to
avoid the GNU GPLv3.  We also learned that recent versions of GDB show
function arguments in the backtrace whereas the GDB included in FreeBSD
apparently doesn't.  Perhaps the situation is similar on NetBSD.

>>>   LICENSE=  gnu-gpl-v3
>>
>> I think this license field is incorrect.  Guile's license is the GNU
>> _Lesser_ General Public License v3-or-later.
>
> Is everything that is installed under LGPL, even readline?
> (But even if so, that should say "gnu-gpl-v3 AND gnu-lgpl-v3".)

The Guile distribution includes an optional 'libguilereadline' library,
which links with libreadline and is covered by GNU GPL v3-or-later.  It
is not used unless explicitly loaded by the user.  Guile itself is
covered by GNU LGPL v3-or-later.

     Regards,
       Mark