[Buildroot] [PATCH v2] python3: add patch to fix PEP 3147 issue with automake built packages

[Arnout Vandecappelle <arnout@mind.be>]

On 12-11-15 16:31, Christophe Vu-Brugier wrote:
> Hi Thomas,
> 
> On Thu, 5 Nov 2015 00:04:20 +0100, Thomas Petazzoni wrote :
>> In fact, it seems that this patch might be causing some Python 3 build
>> issues. See
>> http://autobuild.buildroot.org/results/06e/06e7c654a10a7618c0c64c57bfd9f27e770138fc/build-end.log.
>>
>> Can you have a look?
> 
> Sorry for the late reply.
> 
> Here is a short explanation for the error. The Makefile defines a rule
> to regenerate "Python/importlib.h" if "Lib/importlib/_bootstrap.py" is
> modified using a C helper named `_freeze_importlib`. Since
> "_boostrap.py" is modified by my patch, the rule is invoked. The
> problem is that the helper is built for the target so it cannot be
> executed on the host.
> 
> If I understand correctly "importlib.h" is a frozen module: it contains
> bytecode generated from "_bootstrap.py". It is only used by a dummy
> "frozen.c" program.

 Isn't importlib.h installed to STAGING_DIR where it could be picked up by other
modules?

> 
> I see two options:
> 
> 1/ Patch the Makefile to invoke a version of `_freeze_importlib` built
>    for the host.
> 2/ Simply do not regenerate "importlib.h" because it is not used.

 Most likely, the generated importlib.h doesn't change due to your patch. So the
simplest solution is to do a 'touch $(@D)/Python/importlib.h' in a post-patch
hook (with a large comment explaining why it is necessary and allowed).


 Regards,
 Arnout

> 
> I would favor the second option.
> 
> With best regards,
> 


-- 
Arnout Vandecappelle                          arnout at mind be
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