From 44339cc0b0e29577d882a3c44f3fb22fba110d7d Mon Sep 17 00:00:00 2001
From: Vincent Laporte <Vincent.Laporte@gmail.com>
Date: Tue, 20 Apr 2021 05:33:32 +0200
Subject: [PATCH] ocamlPackages.ocp-build: fix compilation with OCaml 4.12

---
 pkgs/development/tools/ocaml/ocp-build/default.nix | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/pkgs/development/tools/ocaml/ocp-build/default.nix b/pkgs/development/tools/ocaml/ocp-build/default.nix
index 655f7b4d4c2..a1d0b76eb1f 100644
--- a/pkgs/development/tools/ocaml/ocp-build/default.nix
+++ b/pkgs/development/tools/ocaml/ocp-build/default.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchFromGitHub, ocaml, findlib, ncurses, cmdliner, re }:
+{ lib, stdenv, fetchFromGitHub, fetchpatch, ocaml, findlib, ncurses, cmdliner, re }:
 let
   version = "1.99.21";
 in
@@ -13,6 +13,14 @@ stdenv.mkDerivation {
     sha256 = "1641xzik98c7xnjwxpacijd6d9jzx340fmdn6i372z8h554jjlg9";
   };
 
+  patches = [
+    # Fix compilation with OCaml 4.12
+    (fetchpatch {
+      url = "https://github.com/OCamlPro/ocp-build/commit/104e4656ca6dba9edb03b62539c9f1e10abcaae8.patch";
+      sha256 = "0sbyi4acig9q8x1ky4hckfg5pm2nad6zasi51ravaf1spgl148c2";
+    })
+  ];
+
   buildInputs = [ ocaml findlib cmdliner re ];
   propagatedBuildInputs = [ ncurses ];
   preInstall = "mkdir -p $out/bin";