Re: [PATCH] tests/avocado/reverse_debugging: Disable the ppc64 tests by default

["Nicholas Piggin" <npiggin@gmail.com>]

On Wed Nov 15, 2023 at 4:29 AM AEST, Thomas Huth wrote:
> On 14/11/2023 17.37, Philippe Mathieu-Daudé wrote:
> > On 14/11/23 17:31, Thomas Huth wrote:
> >> The tests seem currently to be broken. Disable them by default
> >> until someone fixes them.
> >>
> >> Signed-off-by: Thomas Huth <thuth@redhat.com>
> >> ---
> >>   tests/avocado/reverse_debugging.py | 7 ++++---
> >>   1 file changed, 4 insertions(+), 3 deletions(-)
> > 
> > Similarly, I suspect https://gitlab.com/qemu-project/qemu/-/issues/1961
> > which has a fix ready:
> > https://lore.kernel.org/qemu-devel/20231110170831.185001-1-richard.henderson@linaro.org/
> > 
> > Maybe wait the fix gets in first?
>
> No, I applied Richard's patch, but the problem persists. Does this test 
> still work for you?

I bisected it to 1d4796cd008373 ("python/machine: use socketpair() for
console connections"), which causes this halfway through the test:

2023-11-15 10:37:04,600 stacktrace       L0045 ERROR| Traceback (most recent call last):
2023-11-15 10:37:04,600 stacktrace       L0045 ERROR|   File "/home/npiggin/src/qemu/build/pyvenv/lib/python3.11/site-packages/avocado/core/decorators.py", line 90, in wrapper
2023-11-15 10:37:04,600 stacktrace       L0045 ERROR|     return function(obj, *args, **kwargs)
2023-11-15 10:37:04,600 stacktrace       L0045 ERROR|            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2023-11-15 10:37:04,600 stacktrace       L0045 ERROR|   File "/home/npiggin/src/qemu/build/tests/avocado/reverse_debugging.py", line 264, in test_ppc64_powernv
2023-11-15 10:37:04,600 stacktrace       L0045 ERROR|     self.reverse_debugging()
2023-11-15 10:37:04,600 stacktrace       L0045 ERROR|   File "/home/npiggin/src/qemu/build/tests/avocado/reverse_debugging.py", line 173, in reverse_debugging
2023-11-15 10:37:04,600 stacktrace       L0045 ERROR|     g.cmd(b'c')
2023-11-15 10:37:04,600 stacktrace       L0045 ERROR|   File "/home/npiggin/src/qemu/build/pyvenv/lib/python3.11/site-packages/avocado/utils/gdb.py", line 783, in cmd
2023-11-15 10:37:04,600 stacktrace       L0045 ERROR|     response_payload = self.decode(result)
2023-11-15 10:37:04,600 stacktrace       L0045 ERROR|                        ^^^^^^^^^^^^^^^^^^^
2023-11-15 10:37:04,600 stacktrace       L0045 ERROR|   File "/home/npiggin/src/qemu/build/pyvenv/lib/python3.11/site-packages/avocado/utils/gdb.py", line 738, in decode
2023-11-15 10:37:04,600 stacktrace       L0045 ERROR|     raise InvalidPacketError
2023-11-15 10:37:04,600 stacktrace       L0045 ERROR| avocado.utils.gdb.InvalidPacketError
2023-11-15 10:37:04,600 stacktrace       L0046 ERROR|

It doesn't always fail the same gdb command
(I saw a bc on line 182 as well). It seems to be receiving a
zero length response?

No idea what's happening or why ppc seems to be more fragile.
Or why changing console connection affects gdb connection?

Thanks,
Nick