Package conf-dkml-cross-toolchain

Failed to find a solution:

no platform:
2024-01-29 15:03.10 [INFO] Solving for ocaml-base-compiler, ocaml,
                           conf-dkml-cross-toolchain using opam_repository_commit 251c5edf2ecdd2541c324dacb931c3606ee71eeb

2024-01-29 15:03.15 [INFO] base: eliminated all possibilities in 2.23 s

2024-01-29 15:03.15 [INFO] = base =

2024-01-29 15:03.15 [INFO] Can't find all required versions.
Selected: ocaml-config.3 conf-dkml-cross-toolchain&ocaml&ocaml-base-compiler
          ocaml-system ocaml-base-compiler ocaml-base-compiler
- conf-dkml-cross-toolchain -> conf-dkml-cross-toolchain.4.12.1
    User requested = 4.12.1
- ocaml -> ocaml.4.12.1
    User requested <= 5.1.0
    conf-dkml-cross-toolchain 4.12.1 requires = 4.12.1
- ocaml-base-compiler -> (problem)
    User requested >= 4.04.1
    ocaml-base-compiler|ocaml-variants|ocaml-system|dkml-base-compiler ocaml-base-compiler requires >= 5.0.0~
    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-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.4.14.1: Availability condition not satisfied
      ocaml-system.4.14.0: Availability condition not satisfied
      ...