Cannot install packages on Fedora 31

Learning
1

I am trying to install async_extended and merlin on a new installation of Fedora 31 (no other software installed). The commands

sudo dnf install opam
opam init -a
eval $(opam env)
opam install -y async_extended merlin

result in the final command printing

Sorry, no solution found: there seems to be a problem with your request.

Running opam config report gives opam-version: 2.0.4 and solver: builtin-mccs+glpk.

Do I need a different solver? If so, how do I install on Fedora?

2

Maybe the package list is outdated? Could you try running opam update before the install?

3

If opam does install the latest OCaml version (4.0.9) then merlin is not yet available for this version.

Try running opam without the -y and with the --verbose option

5

Running opam update before the package install results in the same error message. Running opam install --verbose merlin results in the same error message. The version of OCaml installed is indeed 4.0.9.

6

Then you need to wait for this to be merged first https://github.com/ocaml/merlin/pull/1031