gnome-doc-utils: switch to python3

fetch python3 patch from fedora

https://src.fedoraproject.org/rpms/gnome-doc-utils/tree/rawhide

pkgs/development/tools/documentation/gnome-doc-utils/default.nix

@@ -1,7 +1,7 @@
-{ lib, fetchurl, pkg-config, libxml2Python, libxslt, intltool, gnome
-, python2Packages }:
+{ lib, fetchurl, pkg-config, libxml2, libxslt, intltool, gnome
+, python3Packages, fetchpatch, bash }:
 
-python2Packages.buildPythonApplication rec {
+python3Packages.buildPythonApplication rec {
   pname = "gnome-doc-utils";
   version = "0.20.10";
 
@@ -12,28 +12,31 @@ python2Packages.buildPythonApplication rec {
     sha256 = "19n4x25ndzngaciiyd8dd6s2mf9gv6nv3wv27ggns2smm7zkj1nb";
   };
 
+  patches = [
+    # https://bugzilla.redhat.com/show_bug.cgi?id=438638
+    (fetchpatch {
+      url = "https://src.fedoraproject.org/rpms/gnome-doc-utils/raw/6b8908abe5af61a952db7174c5d1843708d61f1b/f/gnome-doc-utils-0.14.0-package.patch";
+      sha256 = "sha256-V2L2/30NoHY/wj3+dsombxveWRSUJb2YByOKtEgVx/0=";
+    })
+    # python3 support
+    (fetchpatch {
+      url = "https://src.fedoraproject.org/rpms/gnome-doc-utils/raw/6b8908abe5af61a952db7174c5d1843708d61f1b/f/gnome-doc-utils-0.20.10-python3.patch";
+      sha256 = "sha256-niH/Yx5H44rsRgkCZS8LWLFB9ZvuInt75zugzoVUhH0=";
+    })
+  ];
+
   nativeBuildInputs = [ intltool pkg-config libxslt.dev ];
-  buildInputs = [ libxslt ];
+  buildInputs = [ libxml2 libxslt bash ];
+  propagatedBuildInputs = [ python3Packages.libxml2 ];
 
   configureFlags = [ "--disable-scrollkeeper" ];
 
-  preBuild = ''
-    substituteInPlace xml2po/xml2po/Makefile --replace '-e "s+^#!.*python.*+#!$(PYTHON)+"' '-e "s\"^#!.*python.*\"#!$(PYTHON)\""'
-  '';
-
-  propagatedBuildInputs = [ libxml2Python ];
-
   passthru = {
     updateScript = gnome.updateScript {
       packageName = pname;
     };
   };
 
-  postFixup = ''
-    # Do not propagate Python
-    rm $out/nix-support/propagated-build-inputs
-  '';
-
   meta = with lib; {
     description = "Collection of documentation utilities for the GNOME project";
     homepage = "https://gitlab.gnome.org/GNOME/gnome-doc-utils";