Package fat-filesystem

Failed to find a solution:

no platform:
2025-05-16 17:28.37 [INFO] Solving for ocaml-base-compiler,
                           fat-filesystem, constraints ocaml-base-compiler<=5.3.0,
                           fat-filesystem=0.12.3 using opam_repository_commit cf409d95af00ff822422bd76b657ed213b661401

2025-05-16 17:28.39 [INFO] base: eliminated all possibilities in 0.61 s

2025-05-16 17:28.39 [INFO] = base =

2025-05-16 17:28.39 [INFO] Can't find all required versions.
Selected: astring.0.8.5 base-bytes.base base-unix.base cmdliner.1.3.0
          conf-pkg-config.4 cppo.1.8.0 csexp.1.5.2 cstruct-lwt.3.7.0
          dune-configurator.3.18.2 fmt.0.10.0 io-page.3.0.0
          jbuilder.transition logs.0.8.0 lwt.5.9.1 mirage-block-lwt.1.2.0
          mirage-fs-lwt.2.0.0 mirage-kv-lwt.2.0.0 num.1.5-1 ocaml.5.5.0
          ocaml-config.3 ocaml-options-vanilla.1 ocamlbuild.0.16.1
          ocamlfind.1.9.8 ocplib-endian.1.2 ppx_cstruct.3.6.0
          ppx_tools_versioned.5.4.0 re.1.12.0 result.1.5 rresult.0.7.0
          seq.base topkg.1.0.8 fat-filesystem&ocaml-base-compiler
          ocaml-variants ocaml-base-compiler ocaml-base-compiler
- cstruct -> cstruct.3.6.0
    cstruct-lwt 3.7.0 requires >= 3.2.0 & < 6.1.0
    fat-filesystem 0.12.3 requires >= 3.0.0 & < 3.7.0
- dune -> (problem)
    cppo 1.8.0 requires >= 2.0
    csexp 1.5.2 requires >= 3.4
    Rejected candidates:
      dune.3.18.2: Requires jbuilder not(= transition)
      dune.3.18.1: Requires jbuilder not(= transition)
      dune.3.18.0: Requires jbuilder not(= transition)
      dune.3.17.2: Requires jbuilder not(= transition)
      dune.3.17.1: Requires jbuilder not(= transition)
      ...
- fat-filesystem -> fat-filesystem.0.12.3
    User requested = 0.12.3
- io-page-unix -> (problem)
    No usable implementations:
      io-page-unix.2.3.0: Availability condition not satisfied
      io-page-unix.2.2.0: Availability condition not satisfied
      io-page-unix.2.1.0: Availability condition not satisfied
      io-page-unix.2.0.1: Availability condition not satisfied
      io-page-unix.2.0.0: Availability condition not satisfied
- mirage-block -> mirage-block.1.2.0
    mirage-block-lwt 1.2.0 requires >= 1.0.0 & < 2.0.0
- mirage-block-unix -> (problem)
    Rejected candidates:
      mirage-block-unix.2.14.2: Requires cstruct >= 6.0.0
      mirage-block-unix.2.14.1: Requires cstruct >= 6.0.0
      mirage-block-unix.2.14.0: Requires ocaml >= 4.06.0 & < 5.0
      mirage-block-unix.2.13.0: Requires ocaml >= 4.06.0 & < 5.0
      mirage-block-unix.2.12.1: Requires ocaml >= 4.06.0 & < 5.0
      ...
- mirage-device -> mirage-device.1.2.0
    mirage-block 1.2.0 requires >= 1.0.0 & < 2.0.0
- mirage-fs -> mirage-fs.2.0.0
    fat-filesystem 0.12.3 requires >= 1.0.0 & < 3.0.0
- mirage-kv -> mirage-kv.2.0.0
    mirage-kv-lwt 2.0.0 requires >= 2.0.0 & < 3.0.0
- ocaml-base-compiler -> ocaml-base-compiler.5.3.0
    User requested <= 5.3.0
- ocaml-compiler -> (problem)
    ocaml-base-compiler 5.3.0 requires = 5.3.0
    Rejected candidates:
      ocaml-compiler.5.5: Incompatible with restriction: = 5.3.0
      ocaml-compiler.5.4: Incompatible with restriction: = 5.3.0
      ocaml-compiler.5.3.0: Requires ocaml = 5.3.0
      ocaml-compiler.5.3.0~rc1: Incompatible with restriction: = 5.3.0
      ocaml-compiler.5.3.0~beta2: Incompatible with restriction: = 5.3.0
      ...
- ocaml-migrate-parsetree -> (problem)
    Rejected candidates:
      ocaml-migrate-parsetree.2.4.0: Requires ocaml >= 4.02.3 & < 5.1
      ocaml-migrate-parsetree.2.3.0: Requires ocaml >= 4.02.3 & < 4.15
      ocaml-migrate-parsetree.2.2.0: Requires ocaml >= 4.02.3 & < 4.14
      ocaml-migrate-parsetree.2.1.0: Requires ocaml >= 4.02.3 & < 4.13
      ocaml-migrate-parsetree.2.0.0: Requires ocaml >= 4.02.3 & < 4.12
      ...
- 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
      ...
- parsexp -> (problem)
    sexplib v0.11.0 requires >= v0.11 & < v0.12
    Rejected candidates:
      parsexp.v0.17.0: Incompatible with restriction: >= v0.11 & < v0.12
      parsexp.v0.16.0: Incompatible with restriction: >= v0.11 & < v0.12
      parsexp.v0.15.0: Incompatible with restriction: >= v0.11 & < v0.12
      parsexp.v0.14.2: Incompatible with restriction: >= v0.11 & < v0.12
      parsexp.v0.14.1: Incompatible with restriction: >= v0.11 & < v0.12
      ...
- ppx_tools -> (problem)
    Rejected candidates:
      ppx_tools.6.6: Requires ocaml >= 4.08.0 & < 5.1.0
      ppx_tools.6.5: Requires ocaml >= 4.08.0 & < 4.15.0
      ppx_tools.6.4: Requires ocaml >= 4.08.0 & < 4.14.0
      ppx_tools.6.3: Requires ocaml >= 4.08.0 & < 4.13.0
      ppx_tools.6.2: Requires ocaml >= 4.08.0 & < 4.12.0
      ...
- sexplib -> sexplib.v0.11.0
    cstruct 3.6.0 requires < v0.12.0
- sexplib0 -> (problem)
    sexplib v0.11.0 requires >= v0.11 & < v0.12
    Rejected candidates:
      sexplib0.v0.17.0: Incompatible with restriction: >= v0.11 & < v0.12
      sexplib0.v0.16.0: Incompatible with restriction: >= v0.11 & < v0.12
      sexplib0.v0.15.1: Incompatible with restriction: >= v0.11 & < v0.12
      sexplib0.v0.15.0: Incompatible with restriction: >= v0.11 & < v0.12
      sexplib0.v0.14.0: Incompatible with restriction: >= v0.11 & < v0.12
      ...