buildDunePackage: new support function; use it to refactor some OCaml derivations

pkgs/development/ocaml-modules/conduit/default.nix

@@ -1,11 +1,11 @@
-{ stdenv, fetchFromGitHub, ocaml, findlib, dune
+{ stdenv, fetchFromGitHub, buildDunePackage
 , ppx_sexp_conv
 , astring, ipaddr, uri
 }:
 
-stdenv.mkDerivation rec {
+buildDunePackage rec {
+  pname = "conduit";
 	version = "1.0.0";
-	name = "ocaml${ocaml.version}-conduit-${version}";
 
 	src = fetchFromGitHub {
 		owner = "mirage";
@@ -14,18 +14,13 @@ stdenv.mkDerivation rec {
 		sha256 = "1ryigzh7sfif1mly624fpm87aw5h60n5wzdlrvqsf71qcpxc6iiz";
 	};
 
-	buildInputs = [ ocaml findlib dune ppx_sexp_conv ];
+	buildInputs = [ ppx_sexp_conv ];
 	propagatedBuildInputs = [ astring ipaddr uri ];
 
-	buildPhase = "dune build -p conduit";
-
-	inherit (dune) installPhase;
-
 	meta = {
 		description = "Network connection library for TCP and SSL";
 		license = stdenv.lib.licenses.isc;
 		maintainers = [ stdenv.lib.maintainers.vbgl ];
 		inherit (src.meta) homepage;
-		inherit (ocaml.meta) platforms;
 	};
 }