On 02.10.2017 12:22, Vinnie Falco via Boost wrote:

On Mon, Oct 2, 2017 at 9:16 AM, Stefan Seefeld via Boost wrote:

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Have you discussed the possibility for the two (Boost.Build and CMake) to coexist... David Sankel made it pretty clear that in the "final solution", CMake will be mandatory and Boost.Build will be optional. Unless I misunderstood (David, feel free to correct me).

Good luck convincing the whole community to adopt that.         Stefan -- ...ich hab' noch einen Koffer in Berlin...

On Tue, Oct 3, 2017 at 8:18 AM, Louis Dionne via Boost wrote:

I don't remember anyone making that statement.

Will Boost.Build be required for new libraries?

On Tue, Oct 3, 2017 at 11:27 AM, Robert Ramey via Boost wrote:

On 10/3/17 8:18 AM, Louis Dionne via Boost wrote:

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Boost - Dev mailing list wrote

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On Mon, Oct 2, 2017 at 9:16 AM, Stefan Seefeld via Boost <

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boost@.boost

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> wrote:

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Have you discussed the possibility for the two (Boost.Build and CMake) to coexist...

David Sankel made it pretty clear that in the "final solution", CMake will be mandatory and Boost.Build will be optional. Unless I misunderstood (David, feel free to correct me).

I don't remember anyone making that statement.

Hmmm - I do remember getting that impression though it may not have been explicitly stated. My reaction was to point out that we didn't have to address this issue until we actually had a real CMake alternative for Boost. I think this got us over the hump to where could find some common ground on something that would move us forward. Of course I don't remember every word and detail now. But I believe that my original summary captures the essential sense of the mercifully short and in my view productive meeting.

I want to revive this old thread, because I think it's extremely important. I've been using CMake since around 2007 and I'm extremely familiar with it. If the Boost developers plan to support CMake or have an ongoing repository with CMake scripts they're working on, please share it with me as I'd love to pitch in. Having said that, I want to be frank. I apologize in advance if this offends anyone. My goal is to not offend anyone's efforts, I just want to be brutally honest for a moment. Boost Build is an abomination of a build system. It's a complex and niche system designed (from my perspective; not sure what the real intent was) just to build boost. It has an extremely steep learning curve and even the most basic build instructions are incredibly complex. Forget cross compiling. Why should I have to define a user-config.jam that specifies over 20 compiler arguments? If you've never tried to build boost for Android, then forget doing it with bjam. First, try doing a google search to see how others have solved the problem. You will literally never see the same solution twice. Furthermore, instructions you find are very dependent on the specific version of NDK and Boost combination used for those instructions. You could spend days going through dozens of solutions but never find one that works. The point of all my venting is that bjam is not sustainable as a public facing build system for Boost. I get that the boost devs are probably already very familiar with it and that makes them comfortable with it. But the users and builders of the Boost library struggle with it constantly. It's not something I have used in my 15+ year career as a software engineer outside of building boost, which I do not do very often. So there's no incentive for me to learn it and become familiar with it beyond the "means to an end" task of getting the libraries I have dependencies on. I've been using a set of comprehensive CMake scripts to build boost here: https://github.com/Orphis/boost-cmake It makes it very easy to build boost consistently across multiple platforms, including cross compiling to Android NDK. Furthermore, the NDK already provides a CMake toolchain file to make the task of building libraries for Android a trivial matter. This project is far from perfect, as it's difficult to add support for building new versions of boost. But I think it's a good start if the boost developers do not have something they're working on already. I've been working with the author to add proper install target support. I've used it and it works great. So it's come a long way and I recommend everyone take a look at it. Lastly I want to just say that supporting multiple build systems simply because a portion of the community is adverse to using CMake is going to be extremely counterproductive. What you'll end up with is the bjam developers not updating CMake, and the CMake developers not updating the bjam build scripts. Happens every where I have worked that has more than one build system in place. I really do not recommend this approach. While more controversial, I recommend that those that currently prefer bjam just make the switch to CMake as long as it fulfills all the requirements. Having people's personal preferences get in the way will just create unnecessary complexity. Just thinking of this objectively. Again I apologize for the frustration that's obviously leaking through my email here. I love boost but for years I've dealt with the frustration of having to build it. It should be a simple matter, but like a some things in boost, the current build system is too overengineered.

-----Original Message----- From: Boost [mailto:boost-bounces@lists.boost.org] On Behalf Of Robert Dailey via Boost Sent: 12 January 2018 15:39 To: Boost Developers Cc: Robert Dailey; Robert Ramey Subject: Re: [boost] [SPAM] Re: Informal CMake meeting at CPPCon

On Tue, Oct 3, 2017 at 11:27 AM, Robert Ramey via Boost wrote:

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On 10/3/17 8:18 AM, Louis Dionne via Boost wrote:

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Boost - Dev mailing list wrote

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On Mon, Oct 2, 2017 at 9:16 AM, Stefan Seefeld via Boost <

...

boost@.boost

...

> wrote:

...

Have you discussed the possibility for the two (Boost.Build and CMake) to coexist...

David Sankel made it pretty clear that in the "final solution", CMake will be mandatory and Boost.Build will be optional. Unless I misunderstood (David, feel free to correct me).

I don't remember anyone making that statement.

Hmmm - I do remember getting that impression though it may not have been explicitly stated. My reaction was to point out that we didn't have to address this issue until we actually had a real CMake alternative for Boost. I think this got us over the hump to where could find some common ground on something that would move us forward. Of course I don't remember every word and detail now. But I believe that my original summary captures the essential sense of the mercifully short and in my view productive meeting.

I want to revive this old thread, because I think it's extremely important. I've been using CMake since around 2007 and I'm extremely familiar with it. If the Boost developers plan to support CMake or have an ongoing repository with CMake scripts they're working on, please share it with me as I'd love to pitch in.

Having said that, I want to be frank. I apologize in advance if this offends anyone. My goal is to not offend anyone's efforts, I just want to be brutally honest for a moment.

Boost Build is an abomination of a build system. It's a complex and niche system designed (from my perspective; not sure what the real intent was) just to build boost. It has an extremely steep learning curve and even the most basic build instructions are incredibly complex. Forget cross compiling. Why should I have to define a user-config.jam that specifies over 20 compiler arguments? If you've never tried to build boost for Android, then forget doing it with bjam. First, try doing a google search to see how others have solved the problem. You will literally never see the same solution twice. Furthermore, instructions you find are very dependent on the specific version of NDK and Boost combination used for those instructions. You could spend days going through dozens of solutions but never find one that works.

The point of all my venting is that bjam is not sustainable as a public facing build system for Boost. I get that the boost devs are probably already very familiar with it and that makes them comfortable with it. But the users and builders of the Boost library struggle with it constantly. It's not something I have used in my 15+ year career as a software engineer outside of building boost, which I do not do very often. So there's no incentive for me to learn it and become familiar with it beyond the "means to an end" task of getting the libraries I have dependencies on.

I've been using a set of comprehensive CMake scripts to build boost here: https://github.com/Orphis/boost-cmake

It makes it very easy to build boost consistently across multiple platforms, including cross compiling to Android NDK. Furthermore, the NDK already provides a CMake toolchain file to make the task of building libraries for Android a trivial matter. This project is far from perfect, as it's difficult to add support for building new versions of boost. But I think it's a good start if the boost developers do not have something they're working on already. I've been working with the author to add proper install target support. I've used it and it works great. So it's come a long way and I recommend everyone take a look at it.

Lastly I want to just say that supporting multiple build systems simply because a portion of the community is adverse to using CMake is going to be extremely counterproductive. What you'll end up with is the bjam developers not updating CMake, and the CMake developers not updating the bjam build scripts. Happens every where I have worked that has more than one build system in place. I really do not recommend this approach. While more controversial, I recommend that those that currently prefer bjam just make the switch to CMake as long as it fulfills all the requirements. Having people's personal preferences get in the way will just create unnecessary complexity. Just thinking of this objectively.

Again I apologize for the frustration that's obviously leaking through my email here. I love boost but for years I've dealt with the frustration of having to build it. It should be a simple matter, but like a some things in boost, the current build system is too overengineered.

I hear your frustration (though I find that bjam works fine for me, and does some things that CMake can't). But, by itself, knocking bjam won't help). There is a clear declared wish and willingness to make CMake work for building Boost. Someone needs to make CMake 'just work' for people (including explaining how - it's all greek to me ;-) ). (And it isn't going to be the people who have worked over many years supporting bjam - it is all they can do to keep bjam running). It's no good trying to stop support for bjam unless CMake is really working well; I don't get the impression that it really is working yet :-( It is lack of CMake enthusiasts input is the missing thing here. So yes, please, help make it happen. HTH Paul --- Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 (0) 1539 561830

On 02.10.2017 13:06, Robert Ramey via Boost wrote:

On 10/2/17 9:16 AM, Stefan Seefeld via Boost wrote:

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Have you discussed the possibility for the two (Boost.Build and CMake) to coexist, by modularizing the build infrastructure such that some libraries might switch to CMake while others might continue using Boost.Build ? I continue to believe that there is no real alternative to such an approach, as you can't coerce anyone into migrating to a new tool, you can only offer a new tool and hope that people will (eventually) migrate.

That happens to be my position as well - see my presentation boost 2.0 from a couple of years ago.  But it's pretty clear that that's a minority opinion.  It's also clear that there is no point in doing much of anything until we have  clear idea how CMake is to be used in the context of boost.

I'm looking for something that we can agree on so some progress can be made.  I'm please that reached a concensus that proposed tools should go through a review process similar to that of libraries.  I think this will be a positive step in helping boost move forward.

It is indeed. Thanks to you all to try to resolve this problem.         Stefan -- ...ich hab' noch einen Koffer in Berlin...

On 02.10.2017 14:20, Niall Douglas via Boost wrote:

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c) And that any such proposals should go through the Boost formal review process.  Traditionally, the boost formal review process has never applied to boost tools so this would be a departure from traditional practice. There is good reason why tooling doesn't go through a formal review process, it could never pass a formal review.

I think that depends on the goal (and metric) of such a review.

I think requiring a cmake conversion to pass a formal review is an impossible ask. The cmake conversion will never reach the quality of the Boost.Build one in any reasonable time period, and moreover, everything keeps shifting with time.

True enough.

I'd support a simple majority, yay or nay vote for the proposed cmake design. Without commentary or review. Makes things feasible. And a second simple majority yay or nay for when Boost.Build is to be turned off (if ever).

I believe you are reaching the wrong conclusions from the above: It's not because a community as big and heterogeneous as Boost can not agree on whether to switch to CMake or to stay with Boost.Build that anyone has the right (or simply the power !) to coerce everyone into accepting a decision made by a few nonetheless. It's simply that the goal is ill-conceived. This is Open Source; it is powered by the people who contribute to and maintain all the projects. You can cheer-lead infrastructure efforts all you want, you do have to accept the decision of those who do the work. (And to be very clear, let me repeat: by "work" I'm not merely referring to the work of migrating, but that of maintaining and simply using the infrastructure day-to-day.) Any effort to help improve our (developers' and maintainers') workflow is *highly* appreciated. But as soon as it's a hindrance rather than help, I have to say: please get out of the way. So, to end on a positive note: I appreciate Robert's mail as it conveys a sense of trying to find consensus. I hope we can build on top of that. Thanks,         Stefan -- ...ich hab' noch einen Koffer in Berlin...

On Mon, 2017-10-02 at 20:31 -0700, Robert Ramey via Boost wrote:

On 10/2/17 11:20 AM, Niall Douglas via Boost wrote:

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c) And that any such proposals should go through the Boost formal review process.  Traditionally, the boost formal review process has never applied to boost tools so this would be a departure from traditional practice.

There is good reason why tooling doesn't go through a formal review process, it could never pass a formal review.

I don't think anyone can know that.

...

I think requiring a cmake conversion to pass a formal review is an impossible ask. 

Doesn't seem impossible to me.

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he cmake conversion will never reach the quality of the Boost.Build

I think that we're here because many believe that CMake has always been  a better alternative than boost build.

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one in any reasonable time period, and moreover, everything keeps shifting with time.

everthing always shifts with time.

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I'd support a simple majority, yay or nay vote for the proposed cmake design. Without commentary or review. Makes things feasible. And a second simple majority yay or nay for when Boost.Build is to be turned off (if ever).

Hmmm - the boost review process is certainly nothing like a simple  yay/nay vote.  This is exactly the reason that the boost librarys are  considered among the best.

Also, there has not been actually been any cmake design submitted.  Paul  has indicated that he believes that it is unnecessary to do this.  So  under these conditions, no boost-like review could be conducted.  So we  are again at a stand still.

No that is not what I am saying at all. The BCM which is like a "library" for cmake will go through a formal review process.  Then after its accepted the cmake build files using BCM will go through an "open" review process and then merged into boost. .