Re: [PATCH] gdb, testsuite: increase timeout in gdb.threads/attach-non-stop.exp

[Simon Marchi <simark@simark.ca>]

On 2026-05-05 02:15, Metzger, Markus T wrote:
> Hello Simon,
> 
>> On 5/4/26 3:16 AM, Markus Metzger wrote:
>>> Attaching sporadically timed out on my system while reading symbols...
>>>
>>>     Reading symbols from .../attach-non-stop...
>>>     (gdb) gdb_do_cache: can_spawn_for_attach (  )
>>>     builtin_spawn .../attach-non-stop
>>>     attach 729532
>>>     Attaching to program: .../attach-non-stop, process 729532
>>>     [New LWP 729574 (id 2)]
>>>     [New LWP 729573 (id 3)]
>>>     [New LWP 729572 (id 4)]
>>>     [New LWP 729571 (id 5)]
>>>     [New LWP 729570 (id 6)]
>>>     [New LWP 729569 (id 7)]
>>>     [New LWP 729568 (id 8)]
>>>     [New LWP 729567 (id 9)]
>>>     [New LWP 729566 (id 10)]
>>>     [New LWP 729565 (id 11)]
>>>     Reading symbols from /lib/x86_64-linux-gnu/libc.so.6...
>>>     FAIL: gdb.threads/attach-non-stop.exp: target-non-stop=off: non-stop=on:
>> cmd=attach: attach (timeout)
>>>
>>> Adjust the timeout to avoid sporadic fails.
>>
>> Not saying it's necessarily a bad idea, but I'd like some more details
>> on what is taking so long.  From the above, I understand that GDB is
>> reading debug info for libc, which is not that big in the grand scheme
>> of things...
>>
>> I'd like to know "this step is taking about X seconds", just to make
>> sure we don't paper over an actual problem.
> 
> The issue happens sporadically, typically while running the entire test
> suite (I use FORCE_PARALLEL).  I tried reproducing it by just running this
> one test but couldn't.
> 
> I cannot say what takes so long and how long exactly it takes, but increasing
> the timeout helped the test pass, so it wasn't actually hanging.  One sporadic
> fail less.

If the timeout is mostly related to how you run the testsuite, then I
think it would be more appropriate to set a local timeout factor.  For
instance, because I build GDB with -O0, with all kinds of checks that
make it slower (_GLIBCXX_DEBUG, ASan), I also get some random timeouts
that are not there when building normally, so I use:

  echo 'set gdb_test_timeout [expr 5 * $timeout]' >> testsuite/site.exp

in my build directory.

Simon