Package merlin

Failed to find a solution:

no platform:
2026-03-03 11:03.46 [INFO] Solving for ocaml-base-compiler,
                           merlin, constraints ocaml-base-compiler<=5.4.0,
                           merlin=5.7-505~preview using opam_repository_commit 344134be6e4a378dcde17e96d4f521174aa1f3f8

2026-03-03 11:04.28 [INFO] base: eliminated all possibilities in 0.25 s

2026-03-03 11:04.28 [INFO] = base =

2026-03-03 11:04.28 [INFO] Can't find all required versions.
Selected: base-threads.base base-unix.base dot-merlin-reader.5.7-505~preview
          dune.3.21.1 ocaml.5.6.0 ocaml-index.5.7-505~preview ocamlfind.1.9.8
          yojson.3.0.0 merlin&ocaml-base-compiler ocaml-base-compiler
- merlin -> merlin.5.7-505~preview
    User requested = 5.7-505~preview
- merlin-lib -> (problem)
    dot-merlin-reader 5.7-505~preview requires = 5.7-505~preview
    Rejected candidates:
      merlin-lib.5.7-505~preview: Requires ocaml >= 5.5 & < 5.6
      merlin-lib.5.6.1-504: Incompatible with restriction: = 5.7-505~preview
      merlin-lib.5.6-504: Incompatible with restriction: = 5.7-505~preview
      merlin-lib.5.6-503: Incompatible with restriction: = 5.7-505~preview
      merlin-lib.5.5-503: Incompatible with restriction: = 5.7-505~preview
      ...
- ocaml-base-compiler -> (problem)
    User requested <= 5.4.0
    ocaml-base-compiler|ocaml-variants|ocaml-system|dkml-base-compiler ocaml-base-compiler requires >= 5.6.0 & < 5.6.1~
    Rejected candidates:
      ocaml-base-compiler.5.4.0: Incompatible with restriction: >= 5.6.0 & < 5.6.1~
      ocaml-base-compiler.5.4.0~rc1: Incompatible with restriction: >= 5.6.0 & < 5.6.1~
      ocaml-base-compiler.5.4.0~beta2: Incompatible with restriction: >= 5.6.0 & < 5.6.1~
      ocaml-base-compiler.5.4.0~beta1: Incompatible with restriction: >= 5.6.0 & < 5.6.1~
      ocaml-base-compiler.5.4.0~alpha1: Incompatible with restriction: >= 5.6.0 & < 5.6.1~
      ...
- odoc -> (problem)
    dune 3.21.1 requires not(< 2.0.1)
    Rejected candidates:
      odoc.3.1.0: Requires ocaml >= 4.08.0 & < 5.5
      odoc.3.0.0: Requires ocaml >= 4.02.0 & < 5.4
      odoc.2.1.1: Requires ocaml >= 4.02.0 & < 5.1
      odoc.1.5.3: Incompatible with restriction: not(< 2.0.1)