OCaml 4.13 Release Readiness

[Octachron]

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:

• opam
• dune
• merlin
• lsp-server / vscode-plugin
• odoc
• ocamlformat
• ocp-indent

Ecosystem:

• ocamlfind
• ocamlbuild
• ppxlib
• ocaml-migrate-parsetree
• mdx
• utop
• dune-release
• opam-publish

Infrastructure:

• ocaml.org
• docker base containers (add ocaml 4.14-dev, opensuse-15.3, deprecate ubuntu 20.10 ocurrent/docker-base-images#115)
• ocaml-ci (update for ocaml 4.14-dev, latest distro list and bump ci-local versions ocurrent/ocaml-ci#345)
• opam-repo-ci (Add OCaml 4.13, switch to OCaml 4.12 by default + add Alpine 3.13 and switch Fedora from 32 to 33 ocurrent/opam-repo-ci#86)

[avsm]

updated the infrastructure bit - no more datakit-ci so replaced it with opam-repo-ci, and marked the containers as working now.

[kit-ty-kate]

We've been testing OCaml 4.13 in opam-repo-ci for a few months already, I've updated that as well

[avsm]

utop now released

[dra27]

lsp-server and merlin are affected by a bug when -principal and -short-paths are both in use (see ocaml/merlin#1389) which should be fixed by the their final 4.13-compatible releases.

[github-actions]

This issue has been open 90 days with no activity. Consequently, it is being marked with the "stale" label. What this means is that the issue will be automatically closed in 30 days unless more comments are added or the "stale" label is removed. If you come across this issue in the future, you may also find it helpful to visit our forum at https://discuss.ocaml.org where queries related to OCaml package management are very welcome.