houdini: easier runtime version substitution

pkgs/applications/misc/houdini/runtime-build.nix

@@ -0,0 +1,35 @@
+{ lib, stdenv, requireFile, bc, version, src, eulaDate }:
+
+let
+  license_dir = "~/.config/houdini";
+in
+stdenv.mkDerivation rec {
+  inherit version src;
+  pname = "houdini-runtime";
+
+  buildInputs = [ bc ];
+  installPhase = ''
+    patchShebangs houdini.install
+    mkdir -p $out
+    ./houdini.install --install-houdini \
+                      --install-license \
+                      --no-install-menus \
+                      --no-install-bin-symlink \
+                      --auto-install \
+                      --no-root-check \
+                      --accept-EULA ${eulaDate} \
+                      $out
+    echo "licensingMode = localValidator" >> $out/houdini/Licensing.opt  # does not seem to do anything any more. not sure, official docs do not say anything about it
+  '';
+
+  dontFixup = true;
+
+  meta = with lib; {
+    description = "3D animation application software";
+    homepage = "https://www.sidefx.com";
+    license = licenses.unfree;
+    platforms = platforms.linux;
+    hydraPlatforms = [ ]; # requireFile src's should be excluded
+    maintainers = with maintainers; [ canndrew kwohlfahrt ];
+  };
+}

pkgs/applications/misc/houdini/runtime.nix

@@ -1,40 +1,14 @@
-{ lib, stdenv, requireFile, bc }:
+{ lib, stdenv, requireFile, callPackage}:
 
 let
   license_dir = "~/.config/houdini";
 in
-stdenv.mkDerivation rec {
+callPackage ./runtime-build.nix rec {
   version = "19.5.569";
-  pname = "houdini-runtime";
+  eulaDate = "2021-10-13";
   src = requireFile rec {
     name = "houdini-${version}-linux_x86_64_gcc9.3.tar.gz";
     sha256 = "0c2d6a31c24f5e7229498af6c3a7cdf81242501d7a0792e4c33b53a898d4999e";
-    url = meta.homepage;
-  };
-
-  buildInputs = [ bc ];
-  installPhase = ''
-    patchShebangs houdini.install
-    mkdir -p $out
-    ./houdini.install --install-houdini \
-                      --install-license \
-                      --no-install-menus \
-                      --no-install-bin-symlink \
-                      --auto-install \
-                      --no-root-check \
-                      --accept-EULA 2021-10-13 \
-                      $out
-    echo "licensingMode = localValidator" >> $out/houdini/Licensing.opt  # does not seem to do anything any more. not sure, official docs do not say anything about it
-  '';
-
-  dontFixup = true;
-
-  meta = with lib; {
-    description = "3D animation application software";
-    homepage = "https://www.sidefx.com";
-    license = licenses.unfree;
-    platforms = platforms.linux;
-    hydraPlatforms = [ ]; # requireFile src's should be excluded
-    maintainers = with maintainers; [ canndrew kwohlfahrt ];
+    url = "https://www.sidefx.com/download/daily-builds/?production=true";
   };
 }