[Buildroot] [PATCH v6 18/28] package/cmake: Fix for using -O in top-level make

[Andreas Naumann]

Hi,

On 19.03.20 15:00, Thomas Petazzoni wrote:
> On Thu, 19 Mar 2020 15:53:23 +0200
> Asaf Kahlon <asafka7 at gmail.com> wrote:
> 
>>> Requiring make > 4.0 on the host system is too strict, especially
>>> considering that the issue we have here only happens in very specific
>>> conditions: ccache support enabled, and passing of custom -O flags that
>>> are only useful for top-level parallel build, which is itself an
>>> experimental feature.
>>
>> Just as a side note - the problem isn't related to ccache. We
>> reproduced it with -O and top-level parallel build.
> 
> Sorry, I mixed things up, and thought it was ccache related.
> 
>> In addition, if you have any suggestion how to address that case -
>> I'll be more than happy to help.
> 
> I don't have any really good suggestion. But it's really a corner case:
> only happens with make 4.1 if I understand correctly, and only when you
> pass some variants of the -O option.
> 
> The "make -Orecurse" option, which is the most relevant for top-level
> parallel build, does not exhibit the issue.
> 
> So essentially I simply wouldn't fix the problem. If you really want to

That's ok for me since it really is a corner case.


regards,
Andreas



> fix it, maybe we can have some fancy logic in the main Makefile to
> detect that one of the problematic -O option is passed, and the make
> version is not appropriate, and then error out.
> 
> Thomas
>