spice-gtk: fix cross compilation

pkgs/development/libraries/spice-gtk/default.nix

@@ -23,6 +23,7 @@
 , libusb1
 , lz4
 , meson
+, mesonEmulatorHook
 , ninja
 , openssl
 , perl
@@ -36,6 +37,7 @@
 , usbredir
 , vala
 , wayland-protocols
+, wayland-scanner
 , zlib
 , withPolkit ? stdenv.isLinux
 }:
@@ -82,6 +84,10 @@ stdenv.mkDerivation rec {
       "# meson.add_install_script('../build-aux/setcap-or-suid',"
   '';
 
+  depsBuildBuild = [
+    pkg-config
+  ];
+
   nativeBuildInputs = [
     docbook_xsl
     gettext
@@ -94,7 +100,10 @@ stdenv.mkDerivation rec {
     python3
     python3.pkgs.pyparsing
     python3.pkgs.six
+    wayland-scanner
     vala
+  ] ++ lib.optionals (stdenv.buildPlatform != stdenv.hostPlatform) [
+    mesonEmulatorHook
   ];
 
   propagatedBuildInputs = [
@@ -118,6 +127,7 @@ stdenv.mkDerivation rec {
     pixman
     spice-protocol
     usbredir
+    vala
     zlib
   ] ++ lib.optionals withPolkit [
     polkit