Add a fix for vcvrack

pkgs/default.nix

@@ -19,6 +19,11 @@ self: super:
   vim-samae = super.callPackage ./vim {};
 
   # Bug fixes:
+  # VCVRack has a bug when used with Xmonad that makes the UI
+  # crash almost immediately There's a workaround documented here
+  # (https://github.com/VCVRack/Rack/issues/478#issuecomment-456174702) and it
+  # requires applying a patch on the source before building.
+  vcv-rack-xmonad = super.callPackage ./vcv-rack {};
 
   scientifica-font = super.callPackage ./scientifica-font {};
   curie-font = super.callPackage ./curie-font {};

pkgs/vcv-rack/default.nix

@@ -0,0 +1,101 @@
+{ stdenv, makeWrapper, fetchFromBitbucket, fetchFromGitHub, pkgconfig
+, alsaLib, curl, glew, glfw, gtk2-x11, jansson, libjack2, libXext, libXi
+, libzip, rtaudio, rtmidi, speex }:
+
+let
+  glfw-git = glfw.overrideAttrs (oldAttrs: rec {
+    name = "glfw-git-${version}";
+    version = "unstable-2018-05-29";
+    src = fetchFromGitHub {
+      owner = "glfw";
+      repo = "glfw";
+      rev = "0be4f3f75aebd9d24583ee86590a38e741db0904";
+      sha256 = "0zbcjgc7ks25yi949k0wjknfl00a4dqmz45mhp00k62vlq2sj0i5";
+    };
+    buildInputs = oldAttrs.buildInputs ++ [ libXext libXi ];
+  });
+  pfft-source = fetchFromBitbucket {
+    owner = "jpommier";
+    repo = "pffft";
+    rev = "29e4f76ac53bef048938754f32231d7836401f79";
+    sha256 = "084csgqa6f1a270bhybjayrh3mpyi2jimc87qkdgsqcp8ycsx1l1";
+  };
+  xmonad-patch = writeText "xmonad-workaround.patch" ''
+    --- a/src/settings.cpp
+    +++ b/src/settings.cpp
+    @@ -20,6 +20,7 @@ static json_t *settingsToJson() {
+     	json_t *tokenJ = json_string(gToken.c_str());
+     	json_object_set_new(rootJ, "token", tokenJ);
+
+    +    /*
+     	if (!windowIsMaximized()) {
+     		// windowSize
+     		Vec windowSize = windowGetWindowSize();
+    @@ -31,6 +32,7 @@ static json_t *settingsToJson() {
+     		json_t *windowPosJ = json_pack("[f, f]", windowPos.x, windowPos.y);
+     		json_object_set_new(rootJ, "windowPos", windowPosJ);
+     	}
+    +    */
+
+     	// opacity
+     	float opacity = gToolbar->wireOpacitySlider->value;
+  '';
+in
+with stdenv.lib; stdenv.mkDerivation rec {
+  name = "VCV-Rack-${version}";
+  version = "0.6.2b";
+
+  src = fetchFromGitHub {
+    owner = "VCVRack";
+    repo = "Rack";
+    rev = "v${version}";
+    sha256 = "17ynhxcci6dyn1yi871fd8yli4924fh12pmk510djwkcj5crhas6";
+    fetchSubmodules = true;
+  };
+
+  prePatch = ''
+    ln -s ${pfft-source} dep/jpommier-pffft-source
+
+    mkdir -p dep/include
+
+    cp dep/jpommier-pffft-source/*.h dep/include
+    cp dep/nanosvg/src/*.h dep/include
+    cp dep/nanovg/src/*.h dep/include
+    cp dep/osdialog/*.h dep/include
+    cp dep/oui-blendish/*.h dep/include
+
+    substituteInPlace include/audio.hpp --replace "<RtAudio.h>" "<rtaudio/RtAudio.h>"
+    substituteInPlace compile.mk --replace "-march=nocona" ""
+    substituteInPlace Makefile \
+       --replace "-Wl,-Bstatic" "" \
+       --replace "-lglfw3" "-lglfw"
+  '';
+
+  enableParallelBuilding = true;
+
+  nativeBuildInputs = [ makeWrapper pkgconfig ];
+  buildInputs = [ glfw-git alsaLib curl glew gtk2-x11 jansson libjack2 libzip rtaudio rtmidi speex ];
+
+  patches = [ xmonad-workaround ];
+  buildFlags = "Rack";
+
+  installPhase = ''
+    install -D -m755 -t $out/bin Rack
+    cp -r res $out/
+
+    mkdir -p $out/share/rack
+    cp LICENSE.txt LICENSE-dist.txt $out/share/rack
+
+    # Override the default global resource file directory
+    wrapProgram $out/bin/Rack --add-flags "-g $out"
+  '';
+
+  meta = with stdenv.lib; {
+    description = "Open-source virtual modular synthesizer";
+    homepage = http://vcvrack.com/;
+    # The source is BSD-3 licensed, some of the art is CC-BY-NC 4.0 or unfree
+    license = [ licenses.bsd3 licenses.cc-by-nc-40 licenses.unfree ];
+    maintainers = with maintainers; [ moredread ];
+    platforms = platforms.linux;
+  };
+}