OCaml 5.1.0 - First Alpha

Four months after the release of OCaml 5.0.0, the set of new features for the future version 5.1.0 of OCaml has been frozen. We are thus happy to announce the first alpha release for OCaml 5.1.0.

This alpha version is here to help fellow hackers join us early in our bug hunting and opam ecosystem fixing fun (see below for the installation instructions). The progresses on stabilising the ecosystem are tracked on the opam readiness for 5.1.0 meta-issue.

If you find any bugs, please report them on OCaml's issue tracker.

Note that this early alpha version is missing two important fixes for the garbage collector and Windows support. Those fixes will be available before the beta. The full release is expected in July.

If you are interested in the ongoing list of new features and bug fixes, the updated change log for OCaml 5.1.0 is available on GitHub.


Installation Instructions

The base compiler can be installed as an opam switch with the following commands on opam 2.1:

opam update
opam switch create 5.1.0~alpha1

For previous version of opam, the switch creation command line is slightly more verbose:

opam update
opam switch create 5.1.0~alpha1 --repositories=default,beta=git+https://github.com/ocaml/ocaml-beta-repository.git

The source code for the alpha is also available at these addresses:

Fine-Tuned Compiler Configuration

If you want to tweak the configuration of the compiler, you can switch to the option variant with:

opam update
opam switch create <switch_name> ocaml-variants.5.1.0~alpha1+options <option_list>

where option_list is a space separated list of ocaml-option-* packages. For instance, for a flambda and no-flat-float-array switch:

opam switch create 5.1.0~alpha1+flambda+nffa ocaml-variants.5.1.0~alpha1+options ocaml-option-flambda ocaml-option-no-flat-float-array

The command line above is slightly more complicated for opam version anterior to 2.1:

opam update
opam switch create <switch_name> --packages=ocaml-variants.5.1.0~alpha1+options,<option_list> --repositories=default,beta=git+https://github.com/ocaml/ocaml-beta-repository.git

In both cases, all available options can be listed with opam search ocaml-option.