File "ocamlbuild_plugin/dune", line 6, characters 12-22:
6 |  (libraries ocamlbuild))
                ^^^^^^^^^^
Error: Library "ocamlbuild" not found.
-> required by library "cppo_ocamlbuild" in _build/default/ocamlbuild_plugin
-> required by _build/default/META.cppo_ocamlbuild
-> required by _build/install/default/lib/cppo_ocamlbuild/META
-> required by _build/default/cppo_ocamlbuild.install
-> required by alias install
-> required by alias default
==> ERROR:(B A failure occurred in build().(B
    Aborting...(B