Why does llvm depend on python 2.7?

[Chris Jones]

Hi,

Seeing as I already have the changes...

https://github.com/macports/macports-ports/pull/6309

Ken - Use as you see fit. Please note though, as I have tried to 
explain, this does not actually in practice change how the build is 
done. On all systems clang-X is configured just as it was before, with 
or without MacPorts python being used. The MR really just removes the 
python27 dep. when it is not actually used.

Chris

On 05/02/2020 2:40 pm, Chris Jones wrote:
> Hi,
> 
> Just to try and be clear. The current inconsistency in the port files is 
> the fact the clang-X builds are configured to *always* depend on python27
> 
> <https://github.com/macports/macports-ports/blob/master/lang/llvm-9.0/Portfile#L54> 
> 
> 
> whereas the clang-X builds is only figured to use this python version 
> for darwin < 11
> 
> <https://github.com/macports/macports-ports/blob/master/lang/llvm-9.0/Portfile#L367> 
> 
> 
> what needs to change is for the port dependency to only be applied when 
> it is actually needed (i.e. used by the build)
> 
> Whether that is only for darwin < 11, as seems to be the current 
> intention, or for all OSes, is really a separate question.
> 
> Chris
> 
> On 05/02/2020 2:33 pm, Chris Jones wrote:
>> Hi,
>>
>> On 05/02/2020 2:18 pm, Ken Cunningham wrote:
>>> doing that doesn't really take us in the right directiion, though chris.
>>>
>>> reproducible builds and all that.
>>>
>>> we go from a fully spec'd proper python 
>>
>> Actually no. That is not what happens at the moment. Check the 
>> clang-9.0 config on darwin 11+ for yourself. The macports python 
>> version is currently *not* used at all. The lines
>>
>>         configure.args-append \
>>              -DPYTHON_EXECUTABLE:FILEPATH=${prefix}/bin/python${py_ver}
>>
>> which configure the clang-X build to use the macports python (2.7) are 
>> *only* used on darwin < 11. On everything else the defaults are used, 
>> which means the cmake build finds and uses /usr/bin/python.
>>
>> to a randomly-found one, in a setting where afaik python 3 is known 
>> not to work.
>>
>> We are already, for the clang-X builds (note I am specifically *not* 
>> talking about llvm-X or lldb-X here) relying on whatever the build 
>> systems decides to used based on its default configuration, for darwin 
>>  >= 11.
>>
>> Now, if you want to *always* spec. the clang-X builds to use *always* 
>> use macports provided python 2.7, that is indeed an option. But that 
>> also requires some fixes in the port file w.r.t. what is currently 
>> done. i.e. remove the darwin  < 11 check at
>>
>> <https://github.com/macports/macports-ports/blob/master/lang/llvm-9.0/Portfile#L367> 
>>
>>
>> so the configuration above is applied to *all* OSes, not just darwin < 
>> 11.
>>
>>>
>>> and I am not sure at present how to even test all the lldb etc 
>>> integration they mention.
>>
>> the changes I am proposing do not touch the lldb-X builds. They 
>> already fully spec. the builds to use macports python, on all OSes.
>>
>> <https://github.com/macports/macports-ports/blob/master/lang/llvm-9.0/Portfile#L317> 
>>
>>
>> Chris
>>
>>>
>>> stripping the python spec is trivial, I could do it in 5 minutes, but 
>>> it doesn't sound like what we should do here...
>>>
>>> ?
>>>
>>> K
>>>