Re: [boost] Deprecation Policy

Subject: Re: [boost] Deprecation Policy
From: Peter Dimov (lists_at_[hidden])
Date: 2015-05-20 19:59:24

Stefan Seefeld wrote:
> On 20/05/15 07:33 PM, Peter Dimov wrote:
> > Stefan Seefeld wrote:
> >
> >> In fact, I believe Boost.Build would be the obvious first choice to 
> >> decouple fully from the rest of Boost, and release separately, but 
> >> that's not my call to make.
> >
> > Like this?
> >
> > https://github.com/boostorg/build/releases/tag/2014.10
> >
> > :-)
>
> Yes, like this. But I think for this really to work efficiently it needs 
> to be taken out of regular Boost releases, as otherwise people will 
> continue using the latter. (And notably, packagers who build binary 
> packages (for example for all the various Linux distributions) will 
> continue building boost-build packages out of Boost releases, rather than 
> the stand-alone Boost.Build releases, which may well lead to confusion and 
> even discrepancies.

I see a slight problem here though (one which you will also encounter when 
you make a standalone release). You have to have a Jamroot somewhere in your 
release. Let's say you take the current Boost and delete everything except 
libs/python, Jamroot, boost-build.jam and boostcpp.jam. You do

    b2 --boost-build=/usr/local/boost-build

(or whatever, I don't know where distributions install Boost.Build), but it 
probably won't work. The reasons it won't is that (a) Jamroot in Boost 1.58 
_probably_ requires Boost.Build 1.58, or perhaps 1.57 at minimum, and you 
may have an earlier version, and (b) it currently includes a project from 
Boost.Config:

    use-project /boost/architecture : libs/config/checks/architecture ;

which it probably needs to implement the architecture feature.

That is, Boost.Build itself is absolutely standalone, but not all 
Boost.Build releases will work with a given Boost release.

Which is very likely why distributions package Boost.Build from the Boost 
release, instead of using a standalone release - it's guaranteed to be 
compatible.