flightgear: darwin support

pkgs/by-name/fl/flightgear/openscenegraph-flightgear.nix

@@ -78,7 +78,10 @@ stdenv.mkDerivation {
     })
   ];
 
-  cmakeFlags = [ "-DBUILD_OSG_APPLICATIONS=OFF" ];
+  cmakeFlags = [
+    (lib.cmakeBool "BUILD_OSG_APPLICATIONS" false)
+  ]
+  ++ lib.optional stdenv.hostPlatform.isDarwin (lib.cmakeFeature "OSG_WINDOWING_SYSTEM" "Cocoa");
 
   meta = {
     description = "3D graphics toolkit";

pkgs/by-name/fl/flightgear/package.nix

@@ -20,6 +20,7 @@
   libxmu,
   libxt,
   simgear,
+  xz,
   zlib,
   boost,
   cmake,
@@ -72,15 +73,29 @@ stdenv.mkDerivation rec {
     qt5.wrapQtAppsHook
   ];
   buildInputs = [
-    libglut
     freealut
+    libjpeg
+    openal
+    plib
+    (simgear.override { openscenegraph = openscenegraph; })
+    zlib
+    boost
+    libpng
+    fltk_1_3
+    apr
+    qt5.qtbase
+    qt5.qtquickcontrols2
+    glew
+    qt5.qtdeclarative
+    curl
+    openscenegraph
+    xz
+  ]
+  ++ lib.optionals (!stdenv.hostPlatform.isDarwin) [
+    libglut
     libGLU
     libGL
     libice
-    libjpeg
-    openal
-    openscenegraph
-    plib
     libsm
     libunwind
     libx11
@@ -89,25 +104,27 @@ stdenv.mkDerivation rec {
     libxi
     libxmu
     libxt
-    (simgear.override { openscenegraph = openscenegraph; })
-    zlib
-    boost
-    libpng
     udev
-    fltk_1_3
-    apr
-    qt5.qtbase
-    qt5.qtquickcontrols2
-    glew
-    qt5.qtdeclarative
-    curl
   ];
 
+  cmakeFlags = lib.optional stdenv.hostPlatform.isDarwin (
+    lib.cmakeFeature "CMAKE_OSX_DEPLOYMENT_TARGET" "11.0"
+  );
+
   qtWrapperArgs = [ "--set FG_ROOT ${data}/share/FlightGear" ];
 
   postInstall = ''
     # Remove redundant AppImage artifacts
     rm -rf "$out/appdir"
+  ''
+  + lib.optionalString stdenv.hostPlatform.isDarwin ''
+    # The bundle copies OSG dylib dangling symlinks
+    rm -rf "$out/FlightGear.app/Contents/Frameworks"
+    # Place app bundle where macOS expects it
+    mkdir -p "$out/Applications"
+    mv "$out/FlightGear.app" "$out/Applications/"
+    # Provide fgfs in bin/ for CLI use, pointing into the bundle
+    ln -s "$out/Applications/FlightGear.app/Contents/MacOS/FlightGear" "$out/bin/fgfs"
   '';
 
   passthru.updateScript = nix-update-script { };
@@ -118,7 +135,7 @@ stdenv.mkDerivation rec {
       raskin
       kirillrdy
     ];
-    platforms = lib.platforms.linux;
+    platforms = lib.platforms.linux ++ lib.platforms.darwin;
     hydraPlatforms = [ ]; # disabled from hydra because it's so big
     license = lib.licenses.gpl2Plus;
     mainProgram = "fgfs";