From b5f580fa2e146c9f326bd64938099a4b5c848a9c Mon Sep 17 00:00:00 2001
From: Vincent Laporte <Vincent.Laporte@gmail.com>
Date: Mon, 10 Dec 2018 19:59:50 +0000
Subject: [PATCH] ocamlPackages.labltk: fix evaluation with OCaml < 4.04

---
 pkgs/development/ocaml-modules/labltk/default.nix | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/pkgs/development/ocaml-modules/labltk/default.nix b/pkgs/development/ocaml-modules/labltk/default.nix
index 10555771feef..b4a4e012560e 100644
--- a/pkgs/development/ocaml-modules/labltk/default.nix
+++ b/pkgs/development/ocaml-modules/labltk/default.nix
@@ -1,5 +1,9 @@
 { stdenv, fetchurl, ocaml, findlib, tcl, tk }:
 
+if !stdenv.lib.versionAtLeast ocaml.version "4.04"
+then throw "labltk is not available for OCaml ${ocaml.version}"
+else
+
 let param = {
   "4.04" = {
     version = "8.06.2";