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.