Re: [Qemu-devel] [PATCH v8 02/13] qemu.py: avoid writing to stdout/stderr

[Kevin Wolf]

Am 01.09.2017 um 13:28 hat Amador Pahim geschrieben:
> This module should not write directly to stdout/stderr. Instead, it
> should either raise exceptions or just log the messages and let the
> callers handle them and decide what to do. For example, scripts could
> choose to send the log messages stderr or/and write them to a file if
> verbose or debugging mode is enabled.
> 
> This patch replaces the writes to stderr by an exception in the
> send_fd_scm() when _socket_scm_helper is not set or not present. In the
> same method, the subprocess Popen will now redirect the stdout/stderr to
> logging.debug instead of writing to system stderr. As consequence, since
> the Popen.communicate() is now used (in order to get the stdout), the
> further call to wait() became redundant and was replaced by
> Popen.returncode.
> 
> The shutdown() message on negative exit code will now be logged
> to logging.warn instead of written to system stderr.
> 
> Signed-off-by: Amador Pahim <address@hidden>
> ---
>  scripts/qemu.py | 30 ++++++++++++++++++++++--------
>  1 file changed, 22 insertions(+), 8 deletions(-)
> 
> diff --git a/scripts/qemu.py b/scripts/qemu.py
> index 0ae5d39414..aca6fa4d82 100644
> --- a/scripts/qemu.py
> +++ b/scripts/qemu.py
> @@ -13,6 +13,7 @@
>  #
>  
>  import errno
> +import logging
>  import string
>  import os
>  import sys
> @@ -20,6 +21,15 @@ import subprocess
>  import qmp.qmp
>  
>  
> +LOG = logging.getLogger(__name__)

This logger isn't properly initialised, so whenever it would actually be
used, the only thing that ends up in the qemu-iotests output is:

+No handlers could be found for logger "qemu"

The actual error message (that was previously logged to stderr) doesn't
make it to the output any more.

I find it sad how the recent test infrastructure "improvements" tend to
break the tests instead of making them easier to work with. Please be a
bit more careful when touching this code, and *test* your code before
you submit it. I expect from anyone that they test their code, but if we
don't even manage to do that for the tests themselves, I'm losing hope.

Kevin