Re: [Qemu-devel] [PULL 19/19] configure: automatically pick python3 is available

[Thomas Huth]

On 03/05/2019 23.34, Eduardo Habkost wrote:
> On Fri, May 03, 2019 at 06:00:11PM -0300, Eduardo Habkost wrote:
>> On Fri, May 03, 2019 at 06:41:43PM +0200, Thomas Huth wrote:
>>> On 03/05/2019 02.41, Eduardo Habkost wrote:
>>>> From: Daniel P. Berrangé <address@hidden>
>>>>
>>>> Unless overridden via an env var or configure arg, QEMU will only look
>>>> for the 'python' binary in $PATH. This is unhelpful on distros which
>>>> are only shipping Python 3.x (eg Fedora) in their default install as,
>>>> if they comply with PEP 394, the bare 'python' binary won't exist.
>>>>
>>>> This changes configure so that by default it will search for all three
>>>> common python binaries, preferring to find Python 3.x versions.
>>>>
>>>> Signed-off-by: Daniel P. Berrangé <address@hidden>
>>>> Message-Id: <address@hidden>
>>>> Signed-off-by: Eduardo Habkost <address@hidden>
>>>> ---
>>>>  configure | 18 +++++++++++++++---
>>>>  1 file changed, 15 insertions(+), 3 deletions(-)
>>>
>>> I haven't bisected it, but I think this patch here broke the gitlab-ci 
>>> tests:
>>>
>>>  https://gitlab.com/huth/qemu/-/jobs/206806257
>>>
>>> Seems like the test is now failing when you don't have an UTF-8 locale:
>>>
>>>  LANG=C make check-qapi-schema
>>
>> I couldn't reproduce it this way, probably because I'm running Python 3.7 
>> which
>> implements PEP 538 ("Coercing the legacy C locale to a UTF-8 based locale").
>>
>> But I can force it to break using:
>>
>>   PYTHONIOENCODING=ascii make check-qapi-schema
>>
>>>  [...]
>>>  TEST    tests/qapi-schema/union-base-empty.out
>>>  --- /builds/huth/qemu/tests/qapi-schema/unicode-str.err    2019-05-03 
>>> 15:21:39.000000000 +0000
>>>  +++ -      2019-05-03 15:42:01.561762978 +0000
>>>  @@ -1 +1 @@
>>>  -tests/qapi-schema/unicode-str.json:2: 'command' uses invalid name 'é'
>>>  +tests/qapi-schema/unicode-str.json:2: 'command' uses invalid name '\xe9'
>>>  /builds/huth/qemu/tests/Makefile.include:1105: recipe for target 
>>> 'check-tests/qapi-schema/unicode-str.json' failed
>>>  make: *** [check-tests/qapi-schema/unicode-str.json] Error 1
>>>
>>> Any ideas how to fix this?
>>
>> Probably we just need to specify an explicit encoding at the statement that
>> prints the error message to stderr.  I will give it a try.
> 
> Forcing a specific encoding inside test-qapi.py would very easy
> on Python 3.7+ (sys.stderr.reconfigure(...)), but tricky on older
> versions.  I believe this is the simplest way to fix the problem
> on Python 3.5 and 3.6.
> 
> Can somebody confirm this really fixes the problem on gitlab-ci?
> 
> ---
> 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 \
>               $^ >$*.test.out 2>$*.test.err; \
>               echo $$? >$*.test.exit, \
>               "TEST","$*.out")

Yes, thanks, this seems to fix this issue:

 https://gitlab.com/huth/qemu/-/jobs/207041381

It also works on my laptop now (which uses Python 3.6).

 Thomas