Package ocaml-options-only-tsan

Failed to find a solution:

no platform:
2025-05-16 17:19.10 [INFO] Solving for ocaml-base-compiler,
                           ocaml-options-only-tsan, constraints ocaml-base-compiler<=5.3.0,
                           ocaml-options-only-tsan=1 using opam_repository_commit cf409d95af00ff822422bd76b657ed213b661401

2025-05-16 17:19.12 [INFO] base: eliminated all possibilities in 0.68 s

2025-05-16 17:19.12 [INFO] = base =

2025-05-16 17:19.12 [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 conf-pkg-config.4
          conf-unwind.0 host-arch-x86_64.1 ocaml.5.5.0 ocaml-compiler.5.5
          ocaml-config.3 ocaml-option-tsan.1 ocaml-variants.5.5.0+trunk
          ocaml-options-only-tsan&ocaml-base-compiler system-mingw
          system-mingw|system-msvc&winpthreads host-arch-x86_64
          ocaml-base-compiler ocaml-base-compiler base-domains ocaml ocaml
- ocaml-base-compiler -> (problem)
    User requested <= 5.3.0
    Rejected candidates:
      ocaml-base-compiler.5.3.0: In same conflict class (ocaml-core-compiler) as ocaml-variants
      ocaml-base-compiler.5.3.0~rc1: In same conflict class (ocaml-core-compiler) as ocaml-variants
      ocaml-base-compiler.5.3.0~beta2: In same conflict class (ocaml-core-compiler) as ocaml-variants
      ocaml-base-compiler.5.3.0~beta1: In same conflict class (ocaml-core-compiler) as ocaml-variants
      ocaml-base-compiler.5.3.0~alpha1: In same conflict class (ocaml-core-compiler) as ocaml-variants
      ...
- ocaml-options-only-tsan -> ocaml-options-only-tsan.1
    User requested = 1
- system-mingw -> (problem)
    No usable implementations:
      system-mingw.1: Availability condition not satisfied