Re: [PATCH] iotests: Revert emulator selection to old behaviour

[Philippe Mathieu-Daudé]

On 2/2/21 3:28 PM, Kevin Wolf wrote:
> If the qemu-system-{arch} binary for the host architecture can't be
> found, the old 'check' implementation selected the alphabetically first
> system emulator binary that it could find. The new Python implementation
> just uses the first result of glob.iglob(), which has an undefined
> order.
> 
> This is a problem that breaks CI because the iotests aren't actually
> prepared to run on any emulator. They should be, so this is really a bug
> in the failing test cases that should be fixed there, but as a quick
> fix, let's revert to the old behaviour to let CI runs succeed again.

FWIW this is the same problem I had 1 year ago and tried to
fix it by sending QMP 'query-version' (introduced in v0.14):
https://www.mail-archive.com/qemu-devel@nongnu.org/msg675075.html

> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  tests/qemu-iotests/testenv.py | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tests/qemu-iotests/testenv.py b/tests/qemu-iotests/testenv.py
> index b31275f518..1fbec854c1 100644
> --- a/tests/qemu-iotests/testenv.py
> +++ b/tests/qemu-iotests/testenv.py
> @@ -135,7 +135,7 @@ class TestEnv(ContextManager['TestEnv']):
>          if not os.path.exists(self.qemu_prog):
>              pattern = root('qemu-system-*')
>              try:
> -                progs = glob.iglob(pattern)
> +                progs = sorted(glob.iglob(pattern))
>                  self.qemu_prog = next(p for p in progs if isxfile(p))
>              except StopIteration:
>                  sys.exit("Not found any Qemu executable binary by pattern "
>