`merlin >= 4.14-502~preview -> ocaml < 5.3` conflicts with everything?

Ecosystem
,
1

I’m just starting out (no serious projects yet), so my current refresh procedure is opam update followed by opam upgrade -y --update--invariant $(opam list -s --roots). Said roots are currently core, merlin, utop, ocamlformat, ocaml – I removed ocaml-base-compiler from the default because it conflicted with ocaml every time (it gets pulled in anyway, I figured). Anyways, today I encountered a problem I did not encounter yesterday:

[ERROR] Package conflict!
  * No agreement on the version of ocaml:
    - ocaml >= 5.3.0
    - merlin >= 4.14-502~preview → ocaml < 5.3
  * Missing dependency:
    - merlin >= 4.14-502~preview → ocaml < 5.3 → ocaml-base-compiler < 3.07+1 |
      ocaml-system < 3.07+1 | ocaml-variants < 3.8~
    unmet availability conditions: 'arch != "arm64" & arch != "arm32" & arch
      != "ppc64"'
    unmet availability conditions: 'sys-ocaml-version = "3.07"'
    no matching version
  * Missing dependency:
    - merlin >= 4.14-502~preview → ocaml < 5.3 → ocaml-base-compiler = 3.07+1 |
      ocaml-system = 3.07+1 | ocaml-variants < 3.8~
    unmet availability conditions: 'arch != "arm64" & arch != "arm32" & arch
      != "ppc64"'
    unmet availability conditions: 'sys-ocaml-version = "3.07+1"'
    no matching version

And it continues for multiple screens.

Near as I can figure, the issue is that opam wants to install a preview version of Merlin for some reason, which looking into it expects ocaml version exactly 5.2, whereas ocaml wants to upgrade to 5.3 (which I wasn’t aware was even out). Then it exhaustively tries every compiler version compatible with 5.3, none of which compile for my system (why is that even shown?).

So, my questions: why is there so much output? How do I stop opam installing previews? Is there really a 5.3 out already or is that another preview? Why is this happening now when I heard there was a PR two years ago that should have fixed it?

I’m on an M3 MacBook Air running macOS Sonoma. My OPAM is from Brew.

2

followed by opam upgrade -y --update--invariant $(opam list -s --roots)

where did you see this refresh procedure from? What are you trying to do?

3

Trial and error, trying to get the most recent compatible versions of all packages in one step. I figure, nothing I’m making now needs to be stable, and new versions tend to fix weirdness which will trip me up heavily at this stage.

Today, a transitive dependency of core expects ocaml earlier than 5.1. It keeps getting stranger.

4

Having now uninstalled and reinstalled everything, I understand the problem: not everything is updated in lockstep, so getting everything mutually compatible sometimes requires stepping things back a bit. It makes sense now I’m thinking about it.