Package depext

Failed to find a solution:

no platform:
2023-08-30 23:52.28 [INFO] Solving for ocaml-base-compiler, ocaml,
                           depext using opam_repository_commit 7dbbdf38edcb4e6e73461f0e7bb2ada6c9314c2f

2023-08-30 23:52.30 [INFO] base: eliminated all possibilities in 0.64 s

2023-08-30 23:52.30 [INFO] = base =

2023-08-30 23:52.30 [INFO] Can't find all required versions.
Selected: base-bigarray.base base-domains.base base-nnp.base
          base-threads.base base-unix.base ocaml-options-vanilla.1
          ocaml-base-compiler&ocaml&depext ocaml base-domains
          ocaml-base-compiler
- depext -> (problem)
    User requested = transition
    No usable implementations:
      depext.transition: Availability condition not satisfied
      depext.1.0.5: Rejected by user-specified constraint depext (= transition)
      depext.1.0.4: Rejected by user-specified constraint depext (= transition)
      depext.1.0.3: Rejected by user-specified constraint depext (= transition)
      depext.1.0.2: Rejected by user-specified constraint depext (= transition)
      ...
- ocaml -> (problem)
    User requested <= 5.0.0
    ocaml-base-compiler 5.1.0~rc2 requires = 5.1.0
    Rejected candidates:
      ocaml.5.0.0: Incompatible with restriction: = 5.1.0
      ocaml.4.14.2: Incompatible with restriction: = 5.1.0
      ocaml.4.14.1: Incompatible with restriction: = 5.1.0
      ocaml.4.14.0: Incompatible with restriction: = 5.1.0
      ocaml.4.13.2: Incompatible with restriction: = 5.1.0
      ...
- ocaml-base-compiler -> ocaml-base-compiler.5.1.0~rc2
    User requested >= 4.04.1