Package core_extended

Failed to find a solution:

no platform:
2024-01-29 14:51.48 [INFO] Solving for ocaml-base-compiler, ocaml,
                           core_extended using opam_repository_commit 251c5edf2ecdd2541c324dacb931c3606ee71eeb

2024-01-29 14:51.53 [INFO] base: eliminated all possibilities in 2.43 s

2024-01-29 14:51.53 [INFO] = base =

2024-01-29 14:51.53 [INFO] Can't find all required versions.
Selected: base-bigarray.base base-domains.base base-nnp.base
          base-threads.base base-unix.base conf-libpcre.1 conf-pkg-config.3
          csexp.1.5.2 dune.3.13.0 dune-configurator.3.13.0 ocaml-config.3
          ocaml-options-vanilla.1 ocamlbuild.0.14.3 pcre.7.5.0
          core_extended&ocaml&ocaml-base-compiler ocaml-base-compiler
          ocaml-base-compiler ocaml base-domains ocaml ocaml-base-compiler
- core -> (problem)
    core_extended 109.12.00 requires = 109.12.00
    Rejected candidates:
      core.v0.16.2: Incompatible with restriction: = 109.12.00
      core.v0.16.1: Incompatible with restriction: = 109.12.00
      core.v0.16.0: Requires ocaml >= 4.14.0 & < 5.1~
      core.v0.15.1: Requires ocaml >= 4.11.0 & < 5.1~
      core.v0.15.0: Requires ocaml >= 4.11.0 & < 5.1~
      ...
- core_extended -> core_extended.109.12.00
    User requested = 109.12.00
- 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~