pa_ppx 0.07

Error log

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

[NOTE] Package dune is already installed (current version is 3.17.2).
[NOTE] Package ocamlfind is already installed (current version is 1.9.8).
[ERROR] Package conflict!
  * Incompatible packages:
    - (invariant) -> ocaml-base-compiler = 4.12.1
    - pa_ppx = 0.07 -> ocaml (>= 4.10.0 & < 4.10.2 | >= 4.11.0 & < 4.11.2 | = 4.12.0) -> ocaml-variants (< 4.11.1~ | >= 4.11.1)
    You can temporarily relax the switch invariant with `--update-invariant'
  * Missing dependency:
    - pa_ppx = 0.07 -> ocaml (>= 4.10.0 & < 4.10.2 | >= 4.11.0 & < 4.11.2 | = 4.12.0) -> ocaml-variants < 4.11.1~ -> ocaml-beta
    unmet availability conditions: 'enable-ocaml-beta-repository'
  * Missing dependency:
    - pa_ppx = 0.07 -> ocaml (>= 4.10.0 & < 4.10.2 | >= 4.11.0 & < 4.11.2 | = 4.12.0) -> ocaml-variants >= 4.11.1 -> system-msvc
    unmet availability conditions: 'os = "win32"'

No solution found, exiting