Merge master into staging-next

pkgs/development/libraries/vtk/generic.nix

@@ -1,5 +1,5 @@
 { majorVersion, minorVersion, sourceSha256, patchesToFetch ? [] }:
-{ stdenv, lib, fetchurl, cmake, libGLU, libGL, libX11, xorgproto, libXt, libtiff
+{ stdenv, lib, fetchurl, cmake, libGLU, libGL, libX11, xorgproto, libXt, libpng, libtiff
 , fetchpatch
 , enableQt ? false, wrapQtAppsHook, qtbase, qtx11extras, qttools
 , enablePython ? false, pythonInterpreter ? throw "vtk: Python support requested, but no python interpreter was given."
@@ -24,7 +24,7 @@ in stdenv.mkDerivation rec {
 
   nativeBuildInputs = [ cmake ];
 
-  buildInputs = [ libtiff ]
+  buildInputs = [ libpng libtiff ]
     ++ optionals enableQt [ qtbase qtx11extras qttools ]
     ++ optionals stdenv.isLinux [
       libGLU
@@ -65,6 +65,7 @@ in stdenv.mkDerivation rec {
   cmakeFlags = [
     "-DCMAKE_C_FLAGS=-fPIC"
     "-DCMAKE_CXX_FLAGS=-fPIC"
+    "-DVTK_USE_SYSTEM_PNG=ON"
     "-DVTK_USE_SYSTEM_TIFF=1"
     "-DOPENGL_INCLUDE_DIR=${libGL}/include"
     "-DCMAKE_INSTALL_LIBDIR=lib"