[Buildroot] [PATCHv2] support/scripts/boot-qemu-image.py: handle when pexpect.spawn() exit early

[Buildroot] [PATCHv2] support/scripts/boot-qemu-image.py: handle when pexpect.spawn() exit early

[Romain Naour]

As reported by a gitlab runtime test [1] and on the mailing list
[2], some runtime tests are failing on slow host machines when
the qemu-system-<arch> is missing on the host.

On such host machines, the "exitstatus:" can be "None" instead of
the qemu-system-<arch> return code value.

This can be reproduced more easily by adding "exit 1" in the
first line of start-qemu.sh (after the shebang).

Add a new condition in the exception handling to check
if exitstatus is not "None" before retrieving the exit code.
If exitstatus is "None", return 127 (command not found) as exit code.

Thanks to Yann for the help while investigating the issue.

Tested:
https://gitlab.com/kubu93/buildroot/pipelines/137465454

[1] https://gitlab.com/kubu93/buildroot/pipelines/135487475
[2] http://lists.busybox.net/pipermail/buildroot/2020-April/280037.html

Fixes:
https://gitlab.com/kubu93/buildroot/-/jobs/509053135

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Cc: Yann E. MORIN <yann.morin.1998@free.fr>
---
v2: Don't sleep(5) (ThomasP)
---
 support/scripts/boot-qemu-image.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/support/scripts/boot-qemu-image.py b/support/scripts/boot-qemu-image.py
index 2c1afba398..f2abaf83ed 100755
--- a/support/scripts/boot-qemu-image.py
+++ b/support/scripts/boot-qemu-image.py
@@ -34,7 +34,7 @@ def main():
         # In this case, spawn above will succeed at starting the wrapper
         # start-qemu.sh, but that one will fail (exit with 127) in such
         # a situation.
-        exit = [int(l.split(' ')[1])
+        exit = [int(l.split(' ')[1] if l is None else int(127))
                 for l in e.value.splitlines()
                 if l.startswith('exitstatus: ')]
         if len(exit) and exit[0] == 127:
-- 
2.25.2

[Buildroot] [PATCHv2] support/scripts/boot-qemu-image.py: handle when pexpect.spawn() exit early

[Thomas Petazzoni]

On Sat, 18 Apr 2020 18:10:23 +0200
Romain Naour <romain.naour@gmail.com> wrote:

> diff --git a/support/scripts/boot-qemu-image.py b/support/scripts/boot-qemu-image.py
> index 2c1afba398..f2abaf83ed 100755
> --- a/support/scripts/boot-qemu-image.py
> +++ b/support/scripts/boot-qemu-image.py
> @@ -34,7 +34,7 @@ def main():
>          # In this case, spawn above will succeed at starting the wrapper
>          # start-qemu.sh, but that one will fail (exit with 127) in such
>          # a situation.
> -        exit = [int(l.split(' ')[1])
> +        exit = [int(l.split(' ')[1] if l is None else int(127))

I know I'm not very good with Python, but if I read this correctly you
are doing l.split() if l is None here, so you're trying to do a
l.split() precisely when is None... Are you sure this is working ?

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

[Buildroot] [PATCHv2] support/scripts/boot-qemu-image.py: handle when pexpect.spawn() exit early

[Yann E. MORIN]

On 2020-04-18 18:47 +0200, Thomas Petazzoni spake thusly:
> On Sat, 18 Apr 2020 18:10:23 +0200
> Romain Naour <romain.naour@gmail.com> wrote:
> 
> > diff --git a/support/scripts/boot-qemu-image.py b/support/scripts/boot-qemu-image.py
> > index 2c1afba398..f2abaf83ed 100755
> > --- a/support/scripts/boot-qemu-image.py
> > +++ b/support/scripts/boot-qemu-image.py
> > @@ -34,7 +34,7 @@ def main():
> >          # In this case, spawn above will succeed at starting the wrapper
> >          # start-qemu.sh, but that one will fail (exit with 127) in such
> >          # a situation.
> > -        exit = [int(l.split(' ')[1])
> > +        exit = [int(l.split(' ')[1] if l is None else int(127))
> 
> I know I'm not very good with Python, but if I read this correctly you
> are doing l.split() if l is None here, so you're trying to do a
> l.split() precisely when is None... Are you sure this is working ?

Besides, it is not None we should test against, but 'None"  (the string
'None', not the object None).

Regards,
Yann E. MORIN.

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