Package async_core

Failed to find a solution:

no platform:
2024-01-29 15:03.40 [INFO] Solving for ocaml-base-compiler, ocaml,
                           async_core using opam_repository_commit 251c5edf2ecdd2541c324dacb931c3606ee71eeb

2024-01-29 15:03.46 [INFO] base: eliminated all possibilities in 2.47 s

2024-01-29 15:03.46 [INFO] = base =

2024-01-29 15:03.46 [INFO] Can't find all required versions.
Selected: base.v0.16.3 base-bigarray.base base-domains.base base-nnp.base
          base-threads.base base-unix.base bin_prot.v0.16.0
          camlp4.4.02.0-1modular-implicits conf-which.1 csexp.1.5.2
          dune.3.13.0 dune-configurator.3.13.0 fieldslib.v0.16.0 num.1.5
          ocaml-compiler-libs.v0.12.4 ocaml-config.3 ocaml-options-vanilla.1
          ocamlbuild.0.14.3 ocamlfind.1.9.6 ounit.2.2.7 ounit2.2.2.7
          pa_ounit.112.24.00 parsexp.v0.16.0 ppx_compare.v0.16.0
          ppx_custom_printf.v0.16.0 ppx_derivers.1.2.1
          ppx_fields_conv.v0.16.0 ppx_optcomp.v0.16.0 ppx_sexp_conv.v0.16.0
          ppx_stable_witness.v0.16.0 ppx_variants_conv.v0.16.0 ppxlib.0.31.0
          seq.base sexplib.v0.16.0 sexplib0.v0.16.0 stdio.v0.16.0
          stdlib-shims.0.3.0 variantslib.v0.16.0
          async_core&ocaml&ocaml-base-compiler ocaml-base-compiler
          ocaml-base-compiler ocaml base-domains ocaml ocaml-base-compiler
- async_core -> async_core.108.00.01
    User requested = 108.00.01
- core -> (problem)
    async_core 108.00.01 requires = 108.00.01
    Rejected candidates:
      core.v0.16.2: Incompatible with restriction: = 108.00.01
      core.v0.16.1: Incompatible with restriction: = 108.00.01
      core.v0.16.0: Incompatible with restriction: = 108.00.01
      core.v0.15.1: Incompatible with restriction: = 108.00.01
      core.v0.15.0: Incompatible with restriction: = 108.00.01
      ...
- 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
      ...
- type_conv -> (problem)
    pa_ounit 112.24.00 requires >= 109.53.00 & < 112.02.00
    Rejected candidates:
      type_conv.113.00.02: Incompatible with restriction: >= 109.53.00 & < 112.02.00
      type_conv.113.00.01: Incompatible with restriction: >= 109.53.00 & < 112.02.00
      type_conv.113.00.00: Incompatible with restriction: >= 109.53.00 & < 112.02.00
      type_conv.112.01.02: Requires ocaml >= 4.02.0 & < 4.03
      type_conv.112.01.01: Requires ocaml >= 4.02.0 & < 4.03
      ...