ocaml-freestanding 0.4.5

Error log

The package failed to build. The error log from opam follows.

[ERROR] Package conflict!
  * No agreement on the version of ocaml:
    - (invariant) -> ocaml-base-compiler = 5.1.1 -> ocaml = 5.1.1
    - ocaml-freestanding = 0.4.5 -> ocaml < 4.08.1
    You can temporarily relax the switch invariant with `--update-invariant'
  * Incompatible packages:
    - (invariant) -> ocaml-base-compiler = 5.1.1
    - ocaml-freestanding = 0.4.5 -> ocaml < 4.08.1 -> ocaml-variants < 4.04.4~
  * Missing dependency:
    - ocaml-freestanding = 0.4.5 -> ocaml < 4.08.1 -> ocaml-base-compiler (<= 3.07+1 | = 3.07+2 | = 3.08.0 | = 3.08.1 | = 3.08.2 | = 3.08.3 | = 3.08.4 | = 3.09.0) | ocaml-system (<= 3.07+1 | = 3.07+2 | >= 3.08.0) | ocaml-variants < 3.09.1~
    not available because the package is pinned to version 5.1.1
    unmet availability conditions, e.g. 'sys-ocaml-version = "5.3.0" & (os != "win32" | sys-ocaml-libc = "msvc")'
    no matching version

No solution found, exiting