Re: [Qemu-devel] [PATCH] tests: Force Python I/O encoding for check-qapi-schema

["Daniel P. Berrangé" <berrange@redhat.com>]

On Mon, May 06, 2019 at 06:38:17PM -0300, Eduardo Habkost wrote:
> test-qapi.py doesn't force a specific encoding for stderr or
> stdout, but the reference files used by check-qapi-schema are in
> UTF-8.  This breaks check-qapi-schema under certain circumstances
> (e.g. if using the C locale and Python < 3.7).
> 
> We need to make sure test-qapi.py always generate UTF-8 output
> somehow.  On Python 3.7+ we can do it using
> `sys.stdout.reconfigure(...)`, but we need a solution that works
> with older Python versions.
> 
> Instead of trying a hack like reopening sys.stdout and
> sys.stderr, we can just tell Python to use UTF-8 for I/O encoding
> when running test-qapi.py.  Do it by setting PYTHONIOENCODING.
> 
> Reported-by: Thomas Huth <thuth@redhat.com>
> Tested-by: Thomas Huth <thuth@redhat.com>
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
>  tests/Makefile.include | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tests/Makefile.include b/tests/Makefile.include
> index 7c8b9c84b2..af88ab6f8b 100644
> --- a/tests/Makefile.include
> +++ b/tests/Makefile.include
> @@ -1103,7 +1103,7 @@ check-tests/qemu-iotests-quick.sh: tests/qemu-iotests-quick.sh qemu-img$(EXESUF)
>  .PHONY: $(patsubst %, check-%, $(check-qapi-schema-y))
>  $(patsubst %, check-%, $(check-qapi-schema-y)): check-%.json: $(SRC_PATH)/%.json
>  	$(call quiet-command, PYTHONPATH=$(SRC_PATH)/scripts \
> -		$(PYTHON) $(SRC_PATH)/tests/qapi-schema/test-qapi.py \
> +		PYTHONIOENCODING=utf-8 $(PYTHON) $(SRC_PATH)/tests/qapi-schema/test-qapi.py \

I see PYTHONIOENCODING exists since 2.6 which is nice.

How about we actually change $(PYTHON) so that it always includes
PYTHONIOENCODING=utf-8 ?

That way we avoid continuing to play whack-a-mole with more utf-8
bugs in future.

It would also let us revert this:

  commit de685ae5e9a4b523513033bd6cadc8187a227170
  Author: Markus Armbruster <armbru@redhat.com>
  Date:   Mon Jun 18 19:59:57 2018 +0200

    qapi: Open files with encoding='utf-8'

which had to provide separate logic for py2 vs py3 :-(

Regards,
Daniel
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