ppx_deriving cannot be installed in the -static switches

[copy]

For example in a ocaml-variants.4.08.1+musl+static+flambda switch:

    ocamlopt src/.ppx_deriving_main.eobjs/native/findlib_initl.{cmx,o}
File "_none_", line 1:
Warning 58: no cmx file was found in path for module Dynlink, and its interface was not compiled with -opaque
    ocamlopt src/.ppx_deriving_main.eobjs/native/ppx_deriving_main.{cmx,o}
File "_none_", line 1:
Warning 58: no cmx file was found in path for module Dynlink, and its interface was not compiled with -opaque
    ocamlopt src/ppx_deriving_main.exe (exit 2)
(cd _build/default && ~/.opam/test/bin/ocamlopt.opt -w -9 -g -o src/ppx_deriving_main.exe -linkall -linkall -I ~/.opam/test/lib/findlib -I ~/.opam/test/lib/ocaml-migrate-parsetree -I ~/.opam/test/lib/ocaml/compiler-libs -I ~/.opam/test/lib/ppx_derivers -I ~/.opam/test/lib/ppx_tools -I ~/.opam/test/lib/result -I src/api ~/.opam/test/lib/ocaml/compiler-libs/ocamlcommon.cmxa ~/.opam/test/lib/ppx_tools/ppx_tools.cmxa ~/.opam/test/lib/result/result.cmxa ~/.opam/test/lib/ppx_derivers/ppx_derivers.cmxa ~/.opam/test/lib/ocaml-migrate-parsetree/migrate_parsetree.cmxa src/api/ppx_deriving_api.cmxa ~/.opam/test/lib/findlib/findlib.cmxa ~/.opam/test/lib/findlib/findlib_dynload.cmxa src/.ppx_deriving_main.eobjs/native/findlib_initl.cmx src/.ppx_deriving_main.eobjs/native/ppx_deriving_main.cmx)
File "_none_", line 1:
Error: No implementations provided for the following modules:
         Dynlink referenced from ~/.opam/test/lib/findlib/findlib_dynload.cmxa(Fl_dynload),
           src/.ppx_deriving_main.eobjs/native/findlib_initl.cmx,
           src/.ppx_deriving_main.eobjs/native/ppx_deriving_main.cmx

Might be the same as backtracking/ocamlgraph#80.