OK so here's my summary of what I've heard here so far:

- Ocaml does not yet have a (public) build system that the majority of users can be happy with for all of their project needs.
- It seems difficult to have a build system that's simple enough to use for small projects, flexible enough to handle the more complicated projects, and that can scale.
- While declarative, dsl-based tools are appealing, they get bogged down as you add features to them, making them become unwieldy.
- A better solution seems to be using a real programming language to describe packages. In our case that should clearly be ocaml itself. The trick is making the API simple.

Looking at some of the the available options:
- ocamlbuild (dsl-based) is a decent basic choice, but lacks advanced features and has become weighed down by multiple file types (_tags, myocamlbuild etc).
- OASIS (dsl-based) seems to be a good description layer for projects, currently farming out the difficult work of building stuff to ocamlbuild, but not really a contender in this race except as an abstraction layer.
- omake (dsl-based) has some fans, but becomes overly-complex for more complicated projects. 
- ocp-build (dsl-based) has had nothing but criticism on this thread. Is there any ongoing work to address these criticisms?
- Jenga (uses ocaml) seems promising but has heavy dependencies, and is currently not geared towards light projects.
- assemblage (uses ocaml) seems promising as well, and seems focused on simplicity. Any comment from assemblage contributors on its status?

Also, while I understand some of the windows hatred, the fact is, most of the world uses windows. Even using cygwin as a translation layer hurts ocaml's ability to reach people. Ideally, a windows programmer could download opam, ocaml and perhaps a mingw compiler, and begin to build projects without any need for a shell or anything POSIX-like. This means that the build system needs to obviate the need for any shell commands or makefiles.

On Thu, Sep 11, 2014 at 6:37 AM, Yaron Minsky <yminsky@janestreet.com> wrote:
On Thu, Sep 11, 2014 at 3:53 AM, Francois Berenger
<francois.berenger@inria.fr> wrote:
> On 09/10/2014 08:59 PM, Yotam Barnoy wrote:
>>
>> Here's part of my motivation for starting this discussion now: I
>> recently experienced a hard-drive failure and had to switch to my backup
>> windows laptop. I was dismayed that opam is still not available for
>> Windows, and while wodi is available, it's not nearly as well developed,
>> and apparently requires many hacks for different packages.
>>
>> It seems to me that these hacks are some of the things that make
>> platform compatibility hard for opam. Each build system has different
>> requirements and methods of compilation, and making this approach
>> cross-platform compatible is difficult. Ideally, a build system will
>> abstract away the things that are not inter-platform compatible. This is
>> why I don't like people using makefiles. Makefiles are not available
>> natively on Windows, and they often contain other bits of shell code
>> that isn't available on all POSIX platforms, let alone on Windows. Not
>> to mention the fact that makefiles have a very tricky and sensitive
>> syntax.
>>
>> I don't expect one build system to match everyone's requirements, but I
>> think if we get together, make a list of requirements, and try to get
>> over our personal biases, we can find something that works for most
>> people, and with some group effort, can work for even more people in
>> more use-cases. I'm not suggesting that we invent something new, but
>> that we take something good and make it better, as well as make an
>> effort to learn that tool and convert packages to use that tool.
>>
>> So here are some requirements I can think of (using some of the
>> suggestions that have been brought up):
>> - Easy to use, especially for small projects (large projects can afford
>> to put more time into their build systems)
>> - Abstract away platform considerations as much as possible. No
>> dependence on specific shells and POSIX utilities.
>> - Allows compilation of C files, which is quite common in ocaml packages.
>> - Scalable to many directories and files
>> - Uses ocamlfind to locate packages
>> - Handles camlp4 and ppx
>> - Parallel & incremental compilation
>>
>> About Jenga: I took a quick look at Jenga, and even though I'm impressed
>> by its capabilities, the amount of code needed to be written even for
>> simple projects is overwhelming. It's clearly a very flexible and
>> powerful tool, but I'd say it's too flexible for the mainstream. There's
>> always room for a build system that's integrated into ocaml itself (like
>> Shake), but I think declarative build systems tend to be easier to
>> comprehend for the average user.
>>
>> ocp-build actually looks very interesting. The manual (which is here:
>>
>> http://github.com/OCamlPro/ocp-build/blob/master/docs/user-manual/user-manual.pdf?raw=true)
>> is incomplete, but contains a nice survey of the existing build tools,
>> and motivation for making ocp-build. Has anyone had experience with
>> ocp-build? Opam seems to be using it, but they also use a makefile
>> (why?) with a bunch of shell commands inside (which is precisely the
>> problem from my perspective). ocp-build is supposedly compatible with
>> Windows, too.
>
>
> Here is one thing I dislike in ocp-build: you have to explicitely list all
> the source files (and maybe same thing for Jenga).

Jenga is quite flexible, so you could write your jengaroot either way
(to demand or not demand explicit source file lists.)  Our internal
jengaroot does not require explicit source file lists.

Not to confuse people, though, Jenga isn't really suitable for people
just picking up and using yet.  We haven't yet written a suitable
jengaroot for general use yet (though there is a version of our
internal jengaroot that we've released, but it's not yet ready for
prime time.)  So Jenga is interesting as an option to discuss, but not
yet a practical option we want to encourage casual users to try.

> I am way too lazy to do that, especially since other tools are able
> to infer this list automatically (a library is just a list of modules,
> an executable has a single entry point, the main function in a single file).
>
>> Yotam
>>
>>
>> On Wed, Sep 10, 2014 at 11:17 AM, Leonardo Laguna Ruiz <modlfo@gmail.com
>> <mailto:modlfo@gmail.com>> wrote:
>>
>>     My pick is ocamlbuild because:
>>
>>     - It works the same way in all platforms that I work (linux,osx,
>>     windows msvc port, cygwin)
>>     - If I can compile ocaml, then I have ocamlbuild
>>     - It does not require external libraries
>>
>>     I have to say that I feel a little bit annoyed by the fact that some
>>     other build systems or tools, do not work correctly in all the
>>     platforms that I want to support.
>>
>>     Leonardo
>>
>>
>>
>>     On 9/10/2014 4:23 PM, Gerd Stolpmann wrote:
>>
>>         Am Mittwoch, den 10.09.2014, 15:29 +0200 schrieb Francois
>> Berenger:
>>
>>             More seriously, concerning build systems, we clearly have
>>             quite some
>>             choice on the OCaml shelf:
>>             - obuild
>>             - ocamlbuild
>>             - omake
>>             - oasis (which in fact uses ocamlbuild, don't forget that)
>>
>>         oasis is not a build system. It is a package description format
>> that
>>         describes how to invoke the build (and more). So far there is only
>>         built-in knowledge for ocamlbuild, but this may change, and you
>> can
>>         already call any external tool, so you can wrap any build system
>> you
>>         want. The intention is here more to create a uniform API for
>>         starting
>>         the build, which may help packagers and other people who
>>         routinely build
>>         software.
>>
>>         Gerd
>>
>>             - jenga
>>             - [...]
>>
>>             My preffered is obuild
>>             (https://github.com/ocaml-__obuild/obuild
>>             <https://github.com/ocaml-obuild/obuild>),
>>             for the terseness, readability and centralization of its build
>>             descriptions. I would love to see the user community of
>>             obuild grow,
>>             so that we can get rid of more bugs, be able to compile _any_
>>             OCaml project with it and implement even more cool features
>>             (contributors are very welcome).
>>
>>             I don't want a ring to rule them all, jut a ring that fits
>>             _my_ finger. ;)
>>
>>             --
>>             Regards,
>>             Francois.
>>
>>
>>
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>>
>
> --
> Regards,
> Francois.
>
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