ocamlPackages.elpi: use recent version of ppxlib

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

@@ -1,5 +1,7 @@
 { stdenv, lib, fetchzip, buildDunePackage, camlp5
-, ppxlib, ppx_deriving, re, perl, ncurses
+, re, perl, ncurses
+, ppxlib, ppx_deriving
+, ppxlib_0_15, ppx_deriving_0_15
 , version ? "1.13.7"
 }:
 with lib;
@@ -23,7 +25,11 @@ buildDunePackage rec {
 
   buildInputs = [ perl ncurses ];
 
-  propagatedBuildInputs = [ camlp5 ppxlib ppx_deriving re ];
+  propagatedBuildInputs = [ camlp5 re ]
+  ++ (if lib.versionAtLeast version "1.13"
+     then [ ppxlib ppx_deriving ]
+     else [ ppxlib_0_15 ppx_deriving_0_15 ]
+  );
 
   meta = {
     description = "Embeddable λProlog Interpreter";

pkgs/top-level/ocaml-packages.nix

@@ -344,8 +344,8 @@ let
         then ppxlib.override { version = "0.15.0"; }
         else ppxlib; in
       {
-        ppx_deriving = ppx_deriving.override { ppxlib = ppxlib_0_15; };
-        ppxlib = ppxlib_0_15;
+        ppx_deriving_0_15 = ppx_deriving.override { ppxlib = ppxlib_0_15; };
+        inherit ppxlib_0_15;
       }
     );