From e69bc44dc72dca17994038826c45336c103f2ed8 Mon Sep 17 00:00:00 2001
From: Florian Klink <flokli@flokli.de>
Date: Mon, 28 Dec 2020 16:45:00 +0100
Subject: [PATCH 1/2] dconf: fix cross compilation

Vala doesn't yet cross-compile, and gtk-doc uses some
gobject-introspection bits (and gobject-introspection doesn't
cross-compile either).
---
 pkgs/development/libraries/dconf/default.nix | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/pkgs/development/libraries/dconf/default.nix b/pkgs/development/libraries/dconf/default.nix
index c9c1b9be922..993e9b8f053 100644
--- a/pkgs/development/libraries/dconf/default.nix
+++ b/pkgs/development/libraries/dconf/default.nix
@@ -15,12 +15,15 @@
 , docbook-xsl-nons
 , docbook_xml_dtd_42
 }:
-
+let
+  isCross = (stdenv.hostPlatform != stdenv.buildPlatform);
+in
 stdenv.mkDerivation rec {
   pname = "dconf";
   version = "0.38.0";
 
-  outputs = [ "out" "lib" "dev" "devdoc" ];
+  outputs = [ "out" "lib" "dev" ]
+    ++ stdenv.lib.optional (!isCross) "devdoc";
 
   src = fetchurl {
     url = "mirror://gnome/sources/${pname}/${stdenv.lib.versions.majorMinor version}/${pname}-${version}.tar.xz";
@@ -30,27 +33,26 @@ stdenv.mkDerivation rec {
   nativeBuildInputs = [
     meson
     ninja
-    vala
     pkg-config
     python3
     libxslt
     libxml2
     glib
-    gtk-doc
     docbook-xsl-nons
     docbook_xml_dtd_42
-  ];
+  ] ++ stdenv.lib.optional (!isCross) gtk-doc;
 
   buildInputs = [
     glib
     bash-completion
     dbus
-  ];
+  ] ++ stdenv.lib.optional (!isCross) vala;
+  # Vala cross compilation is broken. For now, build dconf without vapi when cross-compiling.
 
   mesonFlags = [
     "--sysconfdir=/etc"
-    "-Dgtk_doc=true"
-  ];
+    "-Dgtk_doc=${stdenv.lib.boolToString (!isCross)}" # gtk-doc does do some gobject introspection, which doesn't yet cross-compile.
+  ] ++ stdenv.lib.optional isCross "-Dvapi=false";
 
   doCheck = !stdenv.isAarch32 && !stdenv.isAarch64 && !stdenv.isDarwin;
 

From 195bb483dd1bb33dbfd223bd084869a82b4b2831 Mon Sep 17 00:00:00 2001
From: Florian Klink <flokli@flokli.de>
Date: Mon, 28 Dec 2020 17:56:20 +0100
Subject: [PATCH 2/2] dconf: remove libxml2

This doesn't seem to be required anymore (?)
---
 pkgs/development/libraries/dconf/default.nix | 2 --
 1 file changed, 2 deletions(-)

diff --git a/pkgs/development/libraries/dconf/default.nix b/pkgs/development/libraries/dconf/default.nix
index 993e9b8f053..4b574a17f78 100644
--- a/pkgs/development/libraries/dconf/default.nix
+++ b/pkgs/development/libraries/dconf/default.nix
@@ -10,7 +10,6 @@
 , bash-completion
 , dbus
 , gnome3
-, libxml2
 , gtk-doc
 , docbook-xsl-nons
 , docbook_xml_dtd_42
@@ -36,7 +35,6 @@ stdenv.mkDerivation rec {
     pkg-config
     python3
     libxslt
-    libxml2
     glib
     docbook-xsl-nons
     docbook_xml_dtd_42