How to use beta OCaml compiler via nix shell?

[Zeta611]

Hi, I'd like to use the new ocaml-base-compiler.5.3.0~rc1 via

𝝺 nix shell github:tweag/opam-nix#ocaml-base-compiler.5.3.0~rc1                                                                                                                at 11:08:45
error: flake 'github:tweag/opam-nix' does not provide attribute 'packages.aarch64-darwin.ocaml-base-compiler.5.3.0~rc1', 'legacyPackages.aarch64-darwin.ocaml-base-compiler.5.3.0~rc1' or 'ocaml-base-compiler.5.3.0~rc1'

but getting an error. It works with .latest tag though.

This maybe another question, but is there a way to use utop w/ 5.3.0~rc1 using nix shell as well?
Thanks in advance!

[balsoft]

You need to escape the attribute properly, like this:

nix shell 'github:tweag/opam-nix#ocaml-base-compiler."5.3.0~rc1"'

(mind the nested quotes)

[Zeta611]

Thanks a lot! But now I get that 5.3.0~rc1 is not provided:

error: flake 'github:tweag/opam-nix' does not provide attribute 'packages.x86_64-linux.ocaml-base-compiler."5.3.0~rc1"', 'legacyPackages.x86_64-linux.ocaml-base-compiler."5.3.0~rc1"' or 'ocaml-base-compiler."5.3.0~rc1"'
       Did you mean one of 5.0.0~rc1, 5.1.0~rc1, 5.2.0~rc1, 4.13.0~rc1 or 5.1.0~rc2?

The latest I can use is 5.3.0~beta1, which is strange because I could use 5.3.0~beta2 in a flake+dune based project here.

[balsoft]

Ah, we probably need to update opam-repository.