From acbc4bd3113a4e36189e9f72d27b2a0b44034eda Mon Sep 17 00:00:00 2001
From: Jakob Leifhelm <jakob.leifhelm@gmail.com>
Date: Sun, 18 Jul 2021 15:26:08 +0200
Subject: [PATCH] mixxx: Fix udev rules installation

---
 pkgs/applications/audio/mixxx/default.nix | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/pkgs/applications/audio/mixxx/default.nix b/pkgs/applications/audio/mixxx/default.nix
index 6f0d34b870aa..60591f42e816 100644
--- a/pkgs/applications/audio/mixxx/default.nix
+++ b/pkgs/applications/audio/mixxx/default.nix
@@ -1,4 +1,5 @@
 { lib
+, stdenv
 , mkDerivation
 , fetchurl
 , fetchFromGitHub
@@ -116,6 +117,23 @@ mkDerivation rec {
     "--set LOCALE_ARCHIVE ${glibcLocales}/lib/locale/locale-archive"
   ];
 
+  # mixxx installs udev rules to DATADIR instead of SYSCONFDIR
+  # let's disable this and install udev rules manually via postInstall
+  # see https://github.com/mixxxdj/mixxx/blob/2.3.0/CMakeLists.txt#L1381-L1392
+  cmakeFlags = [
+    "-DINSTALL_USER_UDEV_RULES=OFF"
+  ];
+
+  postInstall = lib.optionalString stdenv.isLinux ''
+    rules="$src/res/linux/mixxx-usb-uaccess.rules"
+    if [ ! -f "$rules" ]; then
+        echo "$rules is missing, must update the Nix file."
+        exit 1
+    fi
+    mkdir -p "$out/lib/udev/rules.d"
+    cp "$rules" "$out/lib/udev/rules.d/69-mixxx-usb-uaccess.rules"
+  '';
+
   meta = with lib; {
     homepage = "https://mixxx.org";
     description = "Digital DJ mixing software";