Package camlp4

Failed to find a solution:

no platform:
2025-05-16 17:15.06 [INFO] Solving for ocaml-base-compiler,
                           camlp4, constraints ocaml-base-compiler<=5.3.0,
                           camlp4=4.12+system using opam_repository_commit cf409d95af00ff822422bd76b657ed213b661401

2025-05-16 17:15.08 [INFO] base: eliminated all possibilities in 0.55 s

2025-05-16 17:15.08 [INFO] = base =

2025-05-16 17:15.08 [INFO] Can't find all required versions.
Selected: ocaml-config.3 ocaml-options-vanilla.1 camlp4&ocaml-base-compiler
          ocaml-variants ocaml-base-compiler ocaml-base-compiler
- camlp4 -> camlp4.4.12+system
    User requested = 4.12+system
- ocaml -> ocaml.4.12.2
    camlp4 4.12+system requires >= 4.12 & < 4.13
- ocaml-base-compiler -> ocaml-base-compiler.5.3.0
    User requested <= 5.3.0
- ocaml-compiler -> (problem)
    ocaml-base-compiler 5.3.0 requires = 5.3.0
    Rejected candidates:
      ocaml-compiler.5.5: Incompatible with restriction: = 5.3.0
      ocaml-compiler.5.4: Incompatible with restriction: = 5.3.0
      ocaml-compiler.5.3.0: Requires ocaml = 5.3.0
      ocaml-compiler.5.3.0~rc1: Incompatible with restriction: = 5.3.0
      ocaml-compiler.5.3.0~beta2: Incompatible with restriction: = 5.3.0
      ...
- ocaml-system -> (problem)
    No usable implementations:
      ocaml-system.5.3.0: Availability condition not satisfied
      ocaml-system.5.2.1: Availability condition not satisfied
      ocaml-system.5.2.0: Availability condition not satisfied
      ocaml-system.5.1.1: Availability condition not satisfied
      ocaml-system.5.1.0: Availability condition not satisfied
      ...
- ocaml-variants -> (problem)
    Rejected candidates:
      ocaml-variants.5.5.0+trunk: In same conflict class (ocaml-core-compiler) as ocaml-base-compiler
      ocaml-variants.5.4.0+trunk: In same conflict class (ocaml-core-compiler) as ocaml-base-compiler
      ocaml-variants.5.3.1+trunk: In same conflict class (ocaml-core-compiler) as ocaml-base-compiler
      ocaml-variants.5.3.0+options: In same conflict class (ocaml-core-compiler) as ocaml-base-compiler
      ocaml-variants.5.3.0+BER: In same conflict class (ocaml-core-compiler) as ocaml-base-compiler
      ...