OCaml 5.0.0 alpha 1 scratch build

[Richard W.M. Jones]

For my sins I'm doing a scratch build of OCaml 5.0.0 alpha 1 here:

https://koji.fedoraproject.org/koji/taskinfo?taskID=91701007

Looking at this there are quite a few larger changes in packaging:

- It seems as if this generates META files for stdlib libraries,
   whereas previously those were generated by ocaml-findlib.  (This is
   a more sensible way to do things, but still a large packaging
   change from our point of view.)

- It puts libraries like dynlink, unix etc into subdirectories,
   previously only threads was in a subdirectory.

- Various extra unexpected files are packaged.  See diff attached.

I'm expecting this will break a lot of things.

5.0.0 also includes multicore support, and is not fully backwards
compatible with all C extensions.  I believe the main change will be
for extensions which are relying on converting raw C pointers to OCaml
pointers without wrapping/hiding them in a Custom value.  An example
of the deprecated behaviour is in ocaml-ancient which is a package I
will likely drop.

Some other useful links:

https://discuss.ocaml.org/t/ocaml-5-0-first-normal-alpha-release/10216
  https://github.com/ocaml/opam-repository/issues/21526
  https://github.com/ocaml/ocaml/blob/5.0/Changes

Rich.

[Jerry James]

On Tue, Sep 6, 2022 at 8:20 AM Richard W.M. Jones  wrote:
> For my sins I'm doing a scratch build of OCaml 5.0.0 alpha 1 here:
>
> https://koji.fedoraproject.org/koji/taskinfo?taskID=91701007

Thanks.  That looks like it will be quite a disruptive change.  I'm
aware of 2 packages I maintain that have new versions that reportedly
support OCaml 5, but which require ocaml-cmdliner >= 1.1.0.  That
version is not backwards compatible with previous versions, so all
users of ocaml-cmdliner will have to be updated simultaneously.

I've got another package that has a new version supporting OCaml 5,
but it needs ocaml-yojson >= 2.0.0 which, you guessed it, is not
backwards compatible with ocaml-yojson 1.x.

This week I am working on a massive update of all GAP packages due to
the release of GAP 4.12.  I hope to start looking at the cmdliner and
yojson issues next week.

Perhaps we should create a COPR repo so we can start figuring out what
works and what is broken.  The repo at
https://copr.fedorainfracloud.org/coprs/jjames/Infer/ is now so
bit-rotted as to be useless.  I should probably just delete it.