From c05d8ea394a97a61bb57ea7c4f6382b0d1aecd5e Mon Sep 17 00:00:00 2001
From: Jan Tojnar <jtojnar@gmail.com>
Date: Tue, 27 Apr 2021 21:26:52 +0200
Subject: [PATCH] gst_all_1.gst-plugins-bad: fix build on Darwin

---
 pkgs/development/libraries/gstreamer/bad/default.nix | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/pkgs/development/libraries/gstreamer/bad/default.nix b/pkgs/development/libraries/gstreamer/bad/default.nix
index 40b10d0983ad..faf38a1a05fb 100644
--- a/pkgs/development/libraries/gstreamer/bad/default.nix
+++ b/pkgs/development/libraries/gstreamer/bad/default.nix
@@ -1,6 +1,7 @@
 { lib
 , stdenv
 , fetchurl
+, fetchpatch
 , meson
 , ninja
 , gettext
@@ -103,6 +104,15 @@ stdenv.mkDerivation rec {
   patches = [
     # Use pkgconfig to inject the includedirs
     ./fix_pkgconfig_includedir.patch
+  ] ++ lib.optionals stdenv.isDarwin [
+    # Fix “error: cannot initialize a parameter of type 'unsigned long *' with an rvalue of type 'typename std::remove_reference<decltype(*(&opencv_dilate_erode_type))>::type *' (aka 'volatile unsigned long *')” on Darwin.
+    (fetchpatch {
+      url = "https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/commit/640a65bf966df065d41a511e2d76d1f26a2e770c.patch";
+      sha256 = "E5pig+qEfR58Jticr6ydFxZOhM3ZJ8zgrf5K4BdiB/Y=";
+      includes = [
+        "ext/opencv/gstcvdilateerode.cpp"
+      ];
+    })
   ];
 
   nativeBuildInputs = [