Package ocaml-variants

Failed to find a solution:

no platform:
2024-05-10 09:29.35 [INFO] Solving for ocaml-base-compiler, ocaml,
                           ocaml-variants using opam_repository_commit 20baedeee4da8e9eb9e3ea43f5dcc631e88de9e6

2024-05-10 09:29.41 [INFO] base: eliminated all possibilities in 2.71 s

2024-05-10 09:29.41 [INFO] = base =

2024-05-10 09:29.41 [INFO] Can't find all required versions.
Selected: base-bigarray.base base-no-ppx.base base-ocamlbuild.base
          base-threads.base base-unix.base camlp4.4.01+system conf-ncurses.1
          conf-pkg-config.3 lwt.2.4.6 ocaml-config.3 ocamlbuild.0
          ocamlfind.1.9.6 ocaml-variants&ocaml&ocaml-base-compiler
          ocaml-base-compiler ocaml-base-compiler base-no-ppx
- ocaml -> ocaml.4.00.1
    User requested <= 5.1.1
    base-no-ppx base requires < 4.02.0
    ocaml-variants 4.00.1+mirage-unix requires = 4.00.1
- ocaml-base-compiler -> (problem)
    User requested >= 4.04.1
    Rejected candidates:
      ocaml-base-compiler.5.2.0~rc1: In same conflict class (ocaml-core-compiler) as ocaml-variants
      ocaml-base-compiler.5.2.0~beta2: In same conflict class (ocaml-core-compiler) as ocaml-variants
      ocaml-base-compiler.5.2.0~beta1: In same conflict class (ocaml-core-compiler) as ocaml-variants
      ocaml-base-compiler.5.2.0~alpha1: In same conflict class (ocaml-core-compiler) as ocaml-variants
      ocaml-base-compiler.5.1.1: In same conflict class (ocaml-core-compiler) as ocaml-variants
      ...
- ocaml-system -> (problem)
    No usable implementations:
      ocaml-system.5.1.1: Availability condition not satisfied
      ocaml-system.5.1.0: Availability condition not satisfied
      ocaml-system.5.0.0: Availability condition not satisfied
      ocaml-system.4.14.2: Availability condition not satisfied
      ocaml-system.4.14.1: Availability condition not satisfied
      ...
- ocaml-variants -> ocaml-variants.4.00.1+mirage-unix
    User requested = 4.00.1+mirage-unix