Re: [PATCH 0/3] Fix gdb.gdb/python-helper.exp + cleanups

[Bruno Larsen <blarsen@redhat.com>]

On 26/09/2022 20:01, Simon Marchi via Gdb-patches wrote:
>
> On 2022-09-23 17:35, Tom de Vries wrote:
>> On 9/23/22 19:02, Luis Machado via Gdb-patches wrote:
>>> On 9/23/22 15:17, Simon Marchi via Gdb-patches wrote:
>>>> My patches that touched TYPE_LENGTH and TYPE_TARGET_TYPE caused
>>>> regressions in gdb.gdb/python-helper.exp.  I forgot to update
>>>> gdb-gdb.py.in, as always.
>>>>
>>>> It looks like my CI doesn't run the test properly.  Because inserting the
>>>> first breakpoint times out, do_self_tests skips the test.  I also had
>>>> troubles running the test locally due to these timeouts.  So the first
>>>> two patches address problems related to that, and the third one is the
>>>> actual fix.
>>>>
>>>> Simon Marchi (3):
>>>>     gdb/testsuite: bump duration for the whole test in do_self_tests
>>>>     gdb/testsuite: use gdb_test in gdb.gdb/python-helper.exp
>>>>     gdb/testsuite: update field names in gdb-gdb.py.in
>>>>
>>>>    gdb/gdb-gdb.py.in                       |  4 +-
>>>>    gdb/testsuite/gdb.gdb/python-helper.exp | 88 +++++--------------------
>>>>    gdb/testsuite/lib/gdb.exp               |  8 +--
>>>>    gdb/testsuite/lib/selftest-support.exp  | 36 +++-------
>>>>    4 files changed, 31 insertions(+), 105 deletions(-)
>>>>
>>>>
>>>> base-commit: 8e037eae6823caf5b9cb5b4feb3de838abb25956
>>> Thanks for the series. I tested this on my end and it seems to work nicely.
>>>
>>> The only hiccup I noticed is when GDB runs into a SIGSEGV due to the guile
>>> interpreter hitting GC_find_limit_with_bound. I'm not sure why this happens. Maybe
>>> it is a problem with guile and armhf.
>> It's documented behaviour of libgc1, see
>> https://sourceware.org/bugzilla/show_bug.cgi?id=29325 .
> Ack, this is an orthogonal issue (and for some reason I don't see it on
> my Arch Linux, but I have certainly seen it elsewhere).

This bug happens because of an old version of libgc being used, where 
they used that segfault to probe memory for something. They have 
developed a new way of probing that doesn't trigger this segfault, but 
not all distributions seem to have backported it. It's probably not 
happening on Arch because htey have a new version of the library, while 
on fedora it was happening until recently (Alexandra backported that for 
us). Fixing this sort of needs to happen on a per-distro basis, as it 
isn't GDB related, it's an "available libraries" problem.

Cheers,
Bruno

>
> Just to confirm, does the series look good to you too Tom?
>
> Simon
>