Package opam-depext

Failed to find a solution:

no platform:
2025-05-16 17:17.36 [INFO] Solving for ocaml-base-compiler,
                           opam-depext, constraints ocaml-base-compiler<=5.3.0,
                           opam-depext=1.1.4 using opam_repository_commit cf409d95af00ff822422bd76b657ed213b661401

2025-05-16 17:17.37 [INFO] base: eliminated all possibilities in 0.55 s

2025-05-16 17:17.37 [INFO] = base =

2025-05-16 17:17.37 [INFO] Can't find all required versions.
Selected: base-bigarray.base base-domains.base base-effects.base
          base-nnp.base base-threads.base base-unix.base ocaml-config.3
          ocaml-options-vanilla.1 opam-depext&ocaml-base-compiler
          system-mingw system-mingw|system-msvc&winpthreads
          ocaml-base-compiler ocaml-base-compiler ocaml base-domains
          ocaml-variants ocaml-base-compiler
- ocaml -> ocaml.5.3.0
    ocaml-compiler 5.3.0 requires = 5.3.0
- ocaml-base-compiler -> ocaml-base-compiler.5.3.0
    User requested <= 5.3.0
- ocaml-compiler -> ocaml-compiler.5.3.0
    ocaml-base-compiler 5.3.0 requires = 5.3.0
- 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
      ...
- opam-depext -> (problem)
    User requested = 1.1.4
    No usable implementations:
      opam-depext.1.2.3: Rejected by user-specified constraint opam-depext (= 1.1.4)
      opam-depext.1.2.1-1: Rejected by user-specified constraint opam-depext (= 1.1.4)
      opam-depext.1.2.1: Rejected by user-specified constraint opam-depext (= 1.1.4)
      opam-depext.1.2.0: Rejected by user-specified constraint opam-depext (= 1.1.4)
      opam-depext.1.1.5: Rejected by user-specified constraint opam-depext (= 1.1.4)
      ...
- system-mingw -> (problem)
    No usable implementations:
      system-mingw.1: Availability condition not satisfied