# OCaml 4.13.0, first alpha release

**URL:** <https://discuss.ocaml.org/t/ocaml-4-13-0-first-alpha-release/7967>\
**Category:** Ecosystem\
**Created:** [June 4, 2021, 6:40pm UTC](https://discuss.ocaml.org/t/ocaml-4-13-0-first-alpha-release/7967 "2021-06-04T18:40:40Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![octachron](https://avatars.discourse-cdn.com/v4/letter/o/49beb7/32.png) [@octachron](https://discuss.ocaml.org/u/octachron)\
**Post date:** [June 4, 2021, 6:40pm UTC](https://discuss.ocaml.org/t/ocaml-4-13-0-first-alpha-release/7967/1 "2021-06-04T18:40:41Z")

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Three months after the release of OCaml 4.12.0, the set of new features for the future version 4.13.0 of OCaml has been frozen. I am thus happy to announce the first alpha release for OCaml 4.13.0 .

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). You can see the progress on this front at

> <https://github.com/ocaml/opam-repository/issues/18791>
>
> This issue tracks the build and readiness information of core platform tools and… libraries in preparation for the OCaml 4.13 release. It’s intended as a meta-issue / holding place for TODO lists and links to other milestones/issues rather than general discussion (which is welcomed on Discuss or on linked issues).
> 
> Packages that are fixed upstream, have a PR ready, or can be used as-is for testing purpose, are in https://github.com/kit-ty-kate/opam-alpha-repository
> 
> \## Platform tools:
> 
> \- \[x\] opam
> \- \[x\] dune
> \- \[x\] merlin
> \- \[x\] lsp-server / vscode-plugin
> \- \[x\] odoc
> \- \[x\] ocamlformat
> \- \[x\] ocp-indent
> 
> \## Ecosystem:
> 
> \- \[x\] ocamlfind
> \- \[x\] ocamlbuild
> \- \[x\] ppxlib
> \- \[x\] ocaml-migrate-parsetree
> \- \[x\] mdx
> \- \[x\] utop
> \- \[x\] dune-release
> \- \[x\] opam-publish
> 
> \## Infrastructure:
> 
> \- \[x\] ocaml.org
> \- \[x\] docker base containers (https://github.com/ocurrent/docker-base-images/pull/115)
> \- \[x\] ocaml-ci (https://github.com/ocurrent/ocaml-ci/pull/345)
> \- \[x\] opam-repo-ci (https://github.com/ocurrent/opam-repo-ci/pull/86)

If you find any bugs, please report them here:

> **[ocaml/ocaml](https://github.com/ocaml/ocaml/issues)**
>
> The core OCaml system: compilers, runtime system, base libraries - ocaml/ocaml

Once most major OCaml tools are supported, we will switch to beta releases.  
The full release is expected to happen in September.

If you are interested by the ongoing list of new features and bug fixes, the  
updated change log for OCaml 4.13.0 is available at:

> <https://github.com/ocaml/ocaml/blob/4.13/Changes>

Note that there is still some on-going work to support improved polling points in preparation  
for OCaml multicore. Another alpha release will be published once this work is merged.

## Installation instructions

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

```auto
opam update
opam switch create 4.13.0~alpha1 --repositories=default,beta=git+https://github.com/ocaml/ocaml-beta-repository.git

```

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

```auto
opam update
opam switch create <switch_name> --packages=ocaml-variants.4.13.0~alpha1+options,<option_list> --repositories=default,beta=git+https://github.com/ocaml/ocaml-beta-repository.git

```

where \<option\_list\> is a comma separated list of ocaml-option-\* packages. For instance, for a flambda and no-flat-float-array switch:

```auto
opam switch create 4.13.0~alpha1+flambda+nffa --packages=ocaml-variants.4.13.0~alpha1+options,ocaml-option-flambda,ocaml-option-no-flat-float-array --repositories=default,beta=git+https://github.com/ocaml/ocaml-beta-repository.git

```

All available options can be listed with “opam search ocaml-option”.

If you want to test this version, it is advised to install the alpha opam repository at

> **[GitHub - kit-ty-kate/opam-alpha-repository: A test opam overlay containing packages compatible...](https://github.com/kit-ty-kate/opam-alpha-repository)**
>
> A test opam overlay containing packages compatible with the next release of the OCaml compiler

with

```bash
opam repo add alpha git://github.com/kit-ty-kate/opam-alpha-repository.git

```

This alpha repository contains various fixes in the process of being upstreamed.

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

[https://github.com/ocaml/ocaml/archive/4.13.0-alpha1.tar.gz](https://github.com/ocaml/ocaml/archive/4.13.0-alpha1.tar.gz)  
[https://caml.inria.fr/pub/distrib/ocaml-4.13/ocaml-4.13.0~alpha1.tar.gz](https://caml.inria.fr/pub/distrib/ocaml-4.13/ocaml-4.13.0~alpha1.tar.gz)

---

<div class="post-metadata">

**Author:** ![tungd](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ocaml.org/tungd/32/2740_2.png) [@tungd](https://discuss.ocaml.org/u/tungd)\
**Post date:** [June 8, 2021, 2:28pm UTC](https://discuss.ocaml.org/t/ocaml-4-13-0-first-alpha-release/7967/2 "2021-06-08T14:28:24Z")

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This might sound a bit silly but among other things, I’m really excited for `String.starts_with`, `String.ends_with` and the new `Array` functions 👍