Hi!
Over the past previous OCaml releases the release-readiness team tried its best to make most packages, and especially core OCaml packages (dune, merlin, ppxlib, …) available day one so people can have the smoothest transition possible to the new compiler release.
Today I’m announcing that merlin (arguably the trickiest core tool to port to new releases, and the most indispensable) is now available to install for early adopters of OCaml 4.13.
To install the latest OCaml 4.13 beta together with Merlin simply call:
$ opam switch create 4.13 --formula='"ocaml-base-compiler" {>= "4.13" & < "4.14"}'
$ opam install merlin
The package is still an early preview. If you encounter any problems while using merlin, please feel free to report it directly in https://github.com/ocaml/merlin/pull/1381
All of the OCaml core packages (with the exception of ocaml-lsp, hopefully soon) should be available out-of-the-box. If some packages aren’t available yet, opam-alpha-repository should have you covered:
$ opam remote add alpha git://github.com/kit-ty-kate/opam-alpha-repository.git
If you have any questions or remarks feel free to ask them here.