From 795fbbf5ccae482a2f670baeb52cedf2d708eac1 Mon Sep 17 00:00:00 2001
From: Dmitry Kalinkin <dmitry.kalinkin@gmail.com>
Date: Fri, 16 Sep 2022 19:22:18 -0400
Subject: [PATCH] ftgl: drop an impure -dylib_file on darwin

The build may outright fail because of this on recent macOS:

ftgl> clang-11: error: no such file or directory: '/System/Library/Frameworks/OpenGL.framework/Versions/A/Libraries/libGL.dylib'
---
 pkgs/development/libraries/ftgl/default.nix | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/pkgs/development/libraries/ftgl/default.nix b/pkgs/development/libraries/ftgl/default.nix
index 466ffcbb73a0..46d6180eb1dc 100644
--- a/pkgs/development/libraries/ftgl/default.nix
+++ b/pkgs/development/libraries/ftgl/default.nix
@@ -23,6 +23,14 @@ stdenv.mkDerivation rec {
     hash = "sha256-6TDNGoMeBLnucmHRgEDIVWcjlJb7N0sTluqBwRMMWn4=";
   };
 
+  # GL_DYLIB is hardcoded to an impure path
+  # /System/Library/Frameworks/OpenGL.framework/Versions/A/Libraries/libGL.dylib
+  # and breaks build on recent macOS versions
+  postPatch = ''
+    substituteInPlace m4/gl.m4 \
+      --replace ' -dylib_file $GL_DYLIB: $GL_DYLIB' ""
+  '';
+
   nativeBuildInputs = [
     autoreconfHook
     doxygen