Re: [boost] Did Boost 1.59.0 change the meaning of "using python : 3.4 : ..." in user-config.jam?

Subject: Re: [boost] Did Boost 1.59.0 change the meaning of "using python : 3.4 : ..." in user-config.jam?
From: Jonathan Wakely (jwakely.boost_at_[hidden])
Date: 2015-08-24 16:31:22

On 24 August 2015 at 18:55, Vladimir Prus wrote:
> On 24-Aug-15 7:04 PM, Jonathan Wakely wrote:
>>>>
>>>> # Python configuration
>>>> -using python : 2.7 : /usr ;
>>>> +import python ;
>>>> +if ! [ python.configured ]
>>>> +{
>>>> +    using python : 2.7 : /usr ;
>>>> +}
>>>>
>>>> path-constant ICU_PATH : /usr ;
>>>>
>>>> So with 1.59.0 the python-2.7 config is only added if
>>>> python.configured is true, but it used to be there unconditionally.
>>>
>>>
>>> Oops, sorry, of course it's only added if it's *false* :-)
>>
>>
>> Changed by
>> https://github.com/boostorg/boost/commit/edca8b1e9317dd6f0ffc46536841708be8480e5d
>
>
> Ah, thanks for tracking this change! I guess the commit has logic to it - if
> one has
> explicit Python configurations, then maybe adding hardcoded 2.7
> configuration is not
> a great idea. Would it be fine with you to just explicitly configure 2.7
> from now on?

Yes, now that I know why it changed it's clear that configuring both
versions explicitly is the right solution.

Thanks for your help finding the cause.