Package async_unix

Failed to find a solution:

no platform:
2024-01-29 15:00.38 [INFO] Solving for ocaml-base-compiler, ocaml,
                           async_unix using opam_repository_commit 251c5edf2ecdd2541c324dacb931c3606ee71eeb

2024-01-29 15:00.44 [INFO] base: eliminated all possibilities in 2.77 s

2024-01-29 15:00.44 [INFO] = base =

2024-01-29 15:00.44 [INFO] Can't find all required versions.
Selected: base-bigarray.base base-domains.base base-nnp.base
          base-threads.base base-unix.base camlp4.4.02.0-1modular-implicits
          conf-which.1 ocaml-config.3 ocaml-options-vanilla.1
          ocamlbuild.0.14.3 ocamlfind.1.9.6
          async_unix&ocaml&ocaml-base-compiler ocaml-base-compiler
          ocaml-base-compiler ocaml base-domains ocaml-base-compiler
- async_core -> async_core.109.15.00
    async_unix 109.15.00 requires = 109.15.00
- async_unix -> async_unix.109.15.00
    User requested = 109.15.00
- core -> (problem)
    async_core 109.15.00 requires >= 109.15.00 & <= 109.18.00
    Rejected candidates:
      core.v0.16.2: Incompatible with restriction: >= 109.15.00 & <= 109.18.00
      core.v0.16.1: Incompatible with restriction: >= 109.15.00 & <= 109.18.00
      core.v0.16.0: Incompatible with restriction: >= 109.15.00 & <= 109.18.00
      core.v0.15.1: Incompatible with restriction: >= 109.15.00 & <= 109.18.00
      core.v0.15.0: Incompatible with restriction: >= 109.15.00 & <= 109.18.00
      ...
- herelib -> (problem)
    async_unix 109.15.00 requires = 109.15.00
    Rejected candidates:
      herelib.112.35.00: Incompatible with restriction: = 109.15.00
      herelib.109.35.02: Incompatible with restriction: = 109.15.00
      herelib.109.35.00: Incompatible with restriction: = 109.15.00
      herelib.109.15.00: Requires ocaml < 4.06.0
      herelib.109.14.00: Incompatible with restriction: = 109.15.00
      ...
- ocaml -> ocaml.5.1.0
    User requested <= 5.1.0
- ocaml-base-compiler -> ocaml-base-compiler.5.1.0
    User requested >= 4.04.1
    ocaml-base-compiler|ocaml-variants|ocaml-system|dkml-base-compiler ocaml-base-compiler requires >= 5.1.0~ & < 5.1.1~
- ocaml-variants -> (problem)
    Rejected candidates:
      ocaml-variants.5.3.0+trunk: In same conflict class (ocaml-core-compiler) as ocaml-base-compiler
      ocaml-variants.5.2.0+trunk: In same conflict class (ocaml-core-compiler) as ocaml-base-compiler
      ocaml-variants.5.1.2+trunk: In same conflict class (ocaml-core-compiler) as ocaml-base-compiler
      ocaml-variants.5.1.1+tsan: In same conflict class (ocaml-core-compiler) as ocaml-base-compiler
      ocaml-variants.5.1.1+options: In same conflict class (ocaml-core-compiler) as ocaml-base-compiler
      ...