Package cstruct

Failed to find a solution:

no platform:
2024-01-29 14:45.50 [INFO] Solving for ocaml-base-compiler, ocaml,
                           cstruct using opam_repository_commit 251c5edf2ecdd2541c324dacb931c3606ee71eeb

2024-01-29 14:45.55 [INFO] base: eliminated all possibilities in 2.59 s

2024-01-29 14:45.55 [INFO] = base =

2024-01-29 14:45.55 [INFO] Can't find all required versions.
Selected: base-bytes.base base-ocamlbuild.base base-threads.base
          base-unix.base camlp4.4.02.0-1modular-implicits conf-time.1
          conf-which.1 cppo.1.6.9 dune.3.13.0 ocaml-config.3
          ocaml-secondary-compiler.4.08.1-1 ocamlbuild.0 ocamlfind.1.9.6
          ocamlfind-secondary.1.9.6 ocplib-endian.1.1 sexplib.113.24.00
          type_conv.113.00.02 cstruct&ocaml&ocaml-base-compiler
          ocaml-base-compiler ocaml-base-compiler ocaml&ocamlfind-secondary
- cstruct -> cstruct.1.8.0
    User requested = 1.8.0
- ocaml -> ocaml.4.02.4
    User requested <= 5.1.0
    base-ocamlbuild base requires >= 3.10 & < 4.03
- ocaml-base-compiler -> (problem)
    User requested >= 4.04.1
    Rejected candidates:
      ocaml-base-compiler.5.1.1: Requires ocaml = 5.1.1
      ocaml-base-compiler.5.1.1~rc1: Requires ocaml = 5.1.1
      ocaml-base-compiler.5.1.0: Requires ocaml = 5.1.0
      ocaml-base-compiler.5.1.0~rc3: Requires ocaml = 5.1.0
      ocaml-base-compiler.5.1.0~rc2: Requires ocaml = 5.1.0
      ...
- ocaml-variants -> (problem)
    camlp4 4.02.0-1modular-implicits requires = 4.02.0+modular-implicits | = 4.02.1+modular-implicits-ber
    Rejected candidates:
      ocaml-variants.5.3.0+trunk: Incompatible with restriction: = 4.02.0+modular-implicits | = 4.02.1+modular-implicits-ber
      ocaml-variants.5.2.0+trunk: Incompatible with restriction: = 4.02.0+modular-implicits | = 4.02.1+modular-implicits-ber
      ocaml-variants.5.1.2+trunk: Incompatible with restriction: = 4.02.0+modular-implicits | = 4.02.1+modular-implicits-ber
      ocaml-variants.5.1.1+tsan: Incompatible with restriction: = 4.02.0+modular-implicits | = 4.02.1+modular-implicits-ber
      ocaml-variants.5.1.1+options: Incompatible with restriction: = 4.02.0+modular-implicits | = 4.02.1+modular-implicits-ber
      ...