try to fix theme

theme-platinum9/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv }:
+{ lib, stdenv, gtk3, adwaita-icon-theme, hicolor-icon-theme }:
 
 stdenv.mkDerivation rec {
   name = "theme-platinum9";
@@ -10,6 +10,17 @@ stdenv.mkDerivation rec {
     rev = version;
   };
 
+  nativeBuildInputs = [
+    gtk3
+  ];
+
+  propagatedBuildInputs = [
+    adwaita-icon-theme
+    hicolor-icon-theme
+  ];
+
+  dontDropIconThemeCache = true;
+
   installPhase = ''
     runHook preInstall
 
@@ -20,8 +31,12 @@ stdenv.mkDerivation rec {
     mv PlatiPlus26 "$out/share/themes"
 
     # Install icons
-    # mkdir -p "$out/share/icons"
-    # mv NineIcons/ "$out/share/icons" 
+    mkdir -p "$out/share/icons"
+    mv NineIcons/ "$out/share/icons" 
+
+    for theme in $out/share/icons/*; do
+      gtk-update-icon-cache "$theme"
+    done
 
     # Install fonts
     mkdir -p "$out/share/fonts/truetype"