diff --git a/pkgs/development/libraries/qt-6/modules/qtbase.nix b/pkgs/development/libraries/qt-6/modules/qtbase.nix
index c0a20503e64c0..da37506d9c16f 100644
--- a/pkgs/development/libraries/qt-6/modules/qtbase.nix
+++ b/pkgs/development/libraries/qt-6/modules/qtbase.nix
@@ -39,6 +39,7 @@
 , libepoxy
 , libiconv
 , dbus
+, dbusSupport ? true
 , fontconfig
 , freetype
 , glib
@@ -68,6 +69,7 @@
 , xcbutilwm
 , zlib
 , at-spi2-core
+, odbcSupport ? stdenv.buildPlatform == stdenv.hostPlatform
 , unixODBC
 , unixODBCDrivers
   # darwin
@@ -94,10 +96,49 @@
 , debug ? false
 , developerBuild ? false
 , qttranslations ? null
+, buildPackages
+, pkgsBuildHost
+, writeText
 }:
 
 let
   debugSymbols = debug || developerBuild;
+
+  # Cross Compilation support
+  #
+  # NOTE!  You must use `targetPlatform` instead of `hostPlatform`
+  # almost everywhere in this file.  This is necessary because our
+  # qtbase expression has "the GCC problem": it builds both a
+  # compiler-like tool (qmake) and its target libraries (qtbase) as
+  # part of a single derivation.  We should stop doing this.
+
+  qtPlatformCross = plat: with plat;
+    if isLinux
+    then "linux-generic-g++"
+    else throw "Please add a qtPlatformCross entry for ${plat.config}";
+
+  specsDirName = "nixpkgs-${stdenv.targetPlatform.config}";
+  specsFile = writeText "qmake.conf" (''
+    MAKEFILE_GENERATOR      = UNIX
+    CONFIG                 += incremental
+    QMAKE_INCREMENTAL_STYLE = sublib
+  '' + lib.optionalString stdenv.hostPlatform.isLinux ''
+    include(../common/linux.conf)
+  '' + lib.optionalString stdenv.cc.isGNU ''
+    include(../common/gcc-base-unix.conf)
+    include(../common/g++-unix.conf)
+  '' + ''
+    QMAKE_CC                = ${stdenv.cc.targetPrefix}gcc
+    QMAKE_CXX               = ${stdenv.cc.targetPrefix}g++
+    QMAKE_LINK              = ${stdenv.cc.targetPrefix}g++
+    QMAKE_LINK_SHLIB        = ${stdenv.cc.targetPrefix}g++
+    QMAKE_AR                = ${stdenv.cc.targetPrefix}ar cqs
+    QMAKE_OBJCOPY           = ${stdenv.cc.targetPrefix}objcopy
+    QMAKE_NM                = ${stdenv.cc.targetPrefix}nm -P
+    QMAKE_STRIP             = ${stdenv.cc.targetPrefix}strip
+    load(qt_config)
+  '');
+
 in
 stdenv.mkDerivation rec {
   pname = "qtbase";
@@ -126,15 +167,18 @@ stdenv.mkDerivation rec {
     double-conversion
     libb2
     md4c
+  ] ++ lib.optionals dbusSupport [
     dbus
+  ] ++ [
     glib
+  ] ++ lib.optionals odbcSupport [
     # unixODBC drivers
     unixODBCDrivers.psql
     unixODBCDrivers.sqlite
     unixODBCDrivers.mariadb
   ] ++ lib.optionals systemdSupport [
     systemd
-  ] ++ lib.optionals stdenv.isLinux [
+  ] ++ lib.optionals stdenv.targetPlatform.isLinux [
     util-linux
     mtdev
     lksctp-tools
@@ -179,6 +223,8 @@ stdenv.mkDerivation rec {
   ] ++ lib.optional libGLSupported libGL;
 
   buildInputs = [
+    python3
+  ] ++ lib.optionals dbusSupport [
     at-spi2-core
   ] ++ lib.optionals (!stdenv.isDarwin) [
     libinput
@@ -208,6 +254,9 @@ stdenv.mkDerivation rec {
     substituteInPlace src/corelib/CMakeLists.txt --replace /bin/ls ${coreutils}/bin/ls
   '' + lib.optionalString stdenv.isDarwin ''
     substituteInPlace cmake/QtAutoDetect.cmake --replace "/usr/bin/xcrun" "${xcbuild}/bin/xcrun"
+  '' + lib.optionalString (stdenv.buildPlatform != stdenv.targetPlatform) ''
+    install -DT ${specsFile}            mkspecs/${specsDirName}/qmake.conf
+    ln -s ../linux-g++/qplatformdefs.h  mkspecs/${specsDirName}/qplatformdefs.h
   '';
 
   fix_qt_builtin_paths = ../hooks/fix-qt-builtin-paths.sh;
@@ -231,10 +280,24 @@ stdenv.mkDerivation rec {
     "-DQT_FEATURE_sctp=ON"
     "-DQT_FEATURE_journald=${if systemdSupport then "ON" else "OFF"}"
     "-DQT_FEATURE_vulkan=ON"
+    "-DQT_FEATURE_dbus=${if dbusSupport then "ON" else "OFF"}"
   ] ++ lib.optionals stdenv.isDarwin [
     # error: 'path' is unavailable: introduced in macOS 10.15
     "-DQT_FEATURE_cxx17_filesystem=OFF"
-  ] ++ lib.optional (qttranslations != null) "-DINSTALL_TRANSLATIONSDIR=${qttranslations}/translations";
+  ] ++ lib.optionals (stdenv.buildPlatform != stdenv.targetPlatform) [
+    # Useful: https://raw.githubusercontent.com/qt/qtbase/dev/cmake/configure-cmake-mapping.md
+    #"-DQT_QMAKE_TARGET_MKSPEC=${specsDirName}"
+    #"-DFEATURE_thread=ON"
+    #"-DQT_BUILD_SHARED_LIBS=ON"
+    #"-DQT_FORCE_BUILD_TOOLS=TRUE"
+    "-DQT_QMAKE_TARGET_MKSPEC=devices/${qtPlatformCross stdenv.hostPlatform}"
+    "-DQT_QMAKE_DEVICE_OPTIONS=CROSS_COMPILE=${stdenv.cc.targetPrefix}"
+
+    #"-DQT_INSTALL_PREFIX=${builtins.placeholder "out"}"
+    "-DQT_HOST_PREFIX=${pkgsBuildHost.qt6Packages.qtbase}"
+  ]
+  #++ lib.optional (qttranslations != null) "-DINSTALL_TRANSLATIONSDIR=${qttranslations}/translations"
+  ;
 
   NIX_LDFLAGS = toString (lib.optionals stdenv.isDarwin [
     # Undefined symbols for architecture arm64: "___gss_c_nt_hostbased_service_oid_desc"
@@ -249,7 +312,11 @@ stdenv.mkDerivation rec {
     moveToOutput      "mkspecs/modules" "$dev"
     fixQtModulePaths  "$dev/mkspecs/modules"
     fixQtBuiltinPaths "$out" '*.pr?'
-  '';
+  ''
+  + lib.optionalString (stdenv.buildPlatform != stdenv.targetPlatform) ''
+    ln -s "${pkgsBuildHost.qt6Packages.qtbase}/libexec/moc" $out/libexec/moc || true
+  ''
+  ;
 
   dontStrip = debugSymbols;
 
diff --git a/pkgs/development/libraries/qt-6/modules/qtdeclarative.nix b/pkgs/development/libraries/qt-6/modules/qtdeclarative.nix
index afdb24d1d291a..d2e4d75024fe4 100644
--- a/pkgs/development/libraries/qt-6/modules/qtdeclarative.nix
+++ b/pkgs/development/libraries/qt-6/modules/qtdeclarative.nix
@@ -1,14 +1,31 @@
-{ qtModule
+{ lib
+, stdenv
+, qtModule
 , qtbase
 , qtlanguageserver
 , qtshadertools
+, qtdeclarative
 , openssl
 , python3
+, buildPackages
+, pkgsBuildBuild
+, pkgsBuildHost
+, pkgsBuildTarget
 }:
 
 qtModule {
   pname = "qtdeclarative";
-  propagatedBuildInputs = [ qtbase qtlanguageserver qtshadertools openssl python3 ];
+  buildInputs = [
+    openssl
+    python3
+    qtbase
+  ];
+  nativeBuildInputs = [
+    python3
+    qtbase
+    qtshadertools
+  ];
+  nativeQtBuildInputs = [ "qtdeclarative" ];
   patches = [
     # prevent headaches from stale qmlcache data
     ../patches/qtdeclarative-default-disable-qmlcache.patch
diff --git a/pkgs/development/libraries/qt-6/modules/qtlocation.nix b/pkgs/development/libraries/qt-6/modules/qtlocation.nix
index 12fa89b9aaead..376ded1d54984 100644
--- a/pkgs/development/libraries/qt-6/modules/qtlocation.nix
+++ b/pkgs/development/libraries/qt-6/modules/qtlocation.nix
@@ -1,10 +1,14 @@
-{ qtModule
+{ lib
+, stdenv
+, qtModule
 , qtbase
 , qtdeclarative
 , qtpositioning
+, pkgsBuildHost
 }:
 
 qtModule {
   pname = "qtlocation";
   propagatedBuildInputs = [ qtbase qtdeclarative qtpositioning ];
+  nativeQtBuildInputs = [ "qtpositioning" "qtdeclarative" ];
 }
diff --git a/pkgs/development/libraries/qt-6/modules/qtmultimedia.nix b/pkgs/development/libraries/qt-6/modules/qtmultimedia.nix
index 538687dce58a0..03e27a2c26bfa 100644
--- a/pkgs/development/libraries/qt-6/modules/qtmultimedia.nix
+++ b/pkgs/development/libraries/qt-6/modules/qtmultimedia.nix
@@ -12,7 +12,7 @@
 , gst-plugins-good
 , gst-libav
 , gst-vaapi
-, libpulseaudio
+, pulseaudioSupport ? stdenv.hostPlatform.isLinux, libpulseaudio
 , wayland
 , elfutils
 , libunwind
@@ -24,11 +24,13 @@ qtModule {
   pname = "qtmultimedia";
   nativeBuildInputs = [ pkg-config ];
   buildInputs = [ libunwind orc ]
-    ++ lib.optionals stdenv.isLinux [ libpulseaudio elfutils alsa-lib wayland ];
-  propagatedBuildInputs = [ qtbase qtdeclarative qtsvg qtshadertools ]
+    ++ lib.optionals pulseaudioSupport [ libpulseaudio ] ++ lib.optionals stdenv.isLinux [ elfutils alsa-lib wayland ];
+  propagatedBuildInputs = [ qtbase qtdeclarative qtsvg ]
     ++ lib.optionals stdenv.isLinux [ gstreamer gst-plugins-base gst-plugins-good gst-libav gst-vaapi ]
     ++ lib.optionals stdenv.isDarwin [ VideoToolbox ];
 
+  nativeQtBuildInputs = [ "qtshadertools" "qtdeclarative" ];
+
   env.NIX_CFLAGS_COMPILE = lib.optionalString stdenv.isDarwin
     "-include AudioToolbox/AudioToolbox.h";
   NIX_LDFLAGS = lib.optionalString stdenv.isDarwin
diff --git a/pkgs/development/libraries/qt-6/modules/qtpositioning.nix b/pkgs/development/libraries/qt-6/modules/qtpositioning.nix
index 20f059976323c..d9546136d2751 100644
--- a/pkgs/development/libraries/qt-6/modules/qtpositioning.nix
+++ b/pkgs/development/libraries/qt-6/modules/qtpositioning.nix
@@ -1,14 +1,19 @@
-{ qtModule
+{ lib
+, stdenv
+, qtModule
 , qtbase
 , qtdeclarative
 , qtserialport
 , pkg-config
 , openssl
+, pkgsBuildHost
 }:
 
 qtModule {
   pname = "qtpositioning";
-  propagatedBuildInputs = [ qtbase qtdeclarative qtserialport ];
-  nativeBuildInputs = [ pkg-config ];
-  buildInputs = [ openssl ];
+  propagatedBuildInputs = [ qtbase qtserialport ];
+  nativeBuildInputs = [ qtbase.dev pkg-config ];
+  buildInputs = [ openssl qtdeclarative ];
+  nativeQtBuildInputs = [ "qtdeclarative" ];
 }
+
diff --git a/pkgs/development/libraries/qt-6/modules/qtquick3d.nix b/pkgs/development/libraries/qt-6/modules/qtquick3d.nix
index 1c84856c0c129..d05b3d3f5c526 100644
--- a/pkgs/development/libraries/qt-6/modules/qtquick3d.nix
+++ b/pkgs/development/libraries/qt-6/modules/qtquick3d.nix
@@ -1,11 +1,19 @@
-{ qtModule
+{ lib
+, stdenv
+, qtModule
 , qtbase
 , qtdeclarative
+, qtshadertools
 , openssl
+, pkgsBuildHost
 }:
 
 qtModule {
   pname = "qtquick3d";
-  propagatedBuildInputs = [ qtbase qtdeclarative ];
-  buildInputs = [ openssl ];
+  propagatedBuildInputs = [ qtbase ];
+  nativeBuildInputs = [ qtshadertools ];
+  nativeQtBuildInputs = [ "qtdeclarative" ];
+  buildInputs = [ openssl qtdeclarative ];
+  dontIgnorePath = true;
 }
+
diff --git a/pkgs/development/libraries/qt-6/modules/qtquicktimeline.nix b/pkgs/development/libraries/qt-6/modules/qtquicktimeline.nix
index 9ac9c1f093934..e6de8135ec74f 100644
--- a/pkgs/development/libraries/qt-6/modules/qtquicktimeline.nix
+++ b/pkgs/development/libraries/qt-6/modules/qtquicktimeline.nix
@@ -1,9 +1,14 @@
-{ qtModule
+{ lib
+, stdenv
+, qtModule
 , qtbase
 , qtdeclarative
+, pkgsBuildHost
 }:
 
 qtModule {
   pname = "qtquicktimeline";
   propagatedBuildInputs = [ qtbase qtdeclarative ];
+  nativeQtBuildInputs = [ "qtdeclarative" ];
 }
+
diff --git a/pkgs/development/libraries/qt-6/modules/qtshadertools.nix b/pkgs/development/libraries/qt-6/modules/qtshadertools.nix
index 5a4b894b9abd6..0337ce1e077be 100644
--- a/pkgs/development/libraries/qt-6/modules/qtshadertools.nix
+++ b/pkgs/development/libraries/qt-6/modules/qtshadertools.nix
@@ -1,8 +1,10 @@
-{ qtModule
+{ lib
+, stdenv
+, qtModule
 , qtbase
 }:
 
 qtModule {
   pname = "qtshadertools";
-  propagatedBuildInputs = [ qtbase ];
+  buildInputs = [ qtbase ];
 }
diff --git a/pkgs/development/libraries/qt-6/modules/qtwayland.nix b/pkgs/development/libraries/qt-6/modules/qtwayland.nix
index ddd402f3c2221..25166885659a4 100644
--- a/pkgs/development/libraries/qt-6/modules/qtwayland.nix
+++ b/pkgs/development/libraries/qt-6/modules/qtwayland.nix
@@ -1,15 +1,22 @@
-{ qtModule
+{ lib
+, stdenv
+, qtModule
 , qtbase
 , qtquick3d
 , qtdeclarative
+, qtwayland
 , wayland
+, wayland-scanner
 , pkg-config
 , libdrm
+, pkgsBuildHost
+, pkgsBuildBuild
 }:
 
 qtModule {
   pname = "qtwayland";
-  propagatedBuildInputs = [ qtbase qtdeclarative ];
-  buildInputs = [ wayland libdrm ];
-  nativeBuildInputs = [ pkg-config ];
+  propagatedBuildInputs = [ qtbase ];
+  buildInputs = [ (lib.getLib wayland) libdrm qtdeclarative ];
+  nativeBuildInputs = [ pkg-config wayland-scanner ];
 }
+
diff --git a/pkgs/development/libraries/qt-6/modules/qtwebchannel.nix b/pkgs/development/libraries/qt-6/modules/qtwebchannel.nix
index bf0ba0f633858..1d211ea18f777 100644
--- a/pkgs/development/libraries/qt-6/modules/qtwebchannel.nix
+++ b/pkgs/development/libraries/qt-6/modules/qtwebchannel.nix
@@ -9,4 +9,5 @@ qtModule {
   pname = "qtwebchannel";
   propagatedBuildInputs = [ qtbase qtdeclarative qtwebsockets ];
   buildInputs = [ openssl ];
+  nativeQtBuildInputs = [ "qtdeclarative" ];
 }
diff --git a/pkgs/development/libraries/qt-6/modules/qtwebengine.nix b/pkgs/development/libraries/qt-6/modules/qtwebengine.nix
index 8670fba6bb2a6..fcf73cc68d591 100644
--- a/pkgs/development/libraries/qt-6/modules/qtwebengine.nix
+++ b/pkgs/development/libraries/qt-6/modules/qtwebengine.nix
@@ -43,11 +43,11 @@
 , libevent
 , openssl
 , alsa-lib
-, pulseaudio
+, pulseaudioSupport ? stdenv.hostPlatform.isLinux, pulseaudio
 , libcap
 , pciutils
 , systemd
-, pipewire
+, pipewireSupport ? stdenv.hostPlatform.isLinux, pipewire
 , gn
 , ffmpeg_4
 , lib
@@ -129,7 +129,9 @@ qtModule {
     # See https://github.com/NixOS/nixpkgs/issues/226484 for more context.
     ../patches/qtwebengine-xkb-includes.patch
 
+  ] ++ lib.optionals pulseaudioSupport [
     ../patches/qtwebengine-link-pulseaudio.patch
+  ] ++ [
 
     # Override locales install path so they go to QtWebEngine's $out
     ../patches/qtwebengine-locales-path.patch
@@ -191,7 +193,7 @@ qtModule {
     # "-DQT_FEATURE_webengine_native_spellchecker=ON"
     "-DQT_FEATURE_webengine_sanitizer=ON"
     "-DQT_FEATURE_webengine_kerberos=ON"
-  ] ++ lib.optionals stdenv.isLinux [
+  ] ++ lib.optionals pipewireSupport [
     "-DQT_FEATURE_webengine_webrtc_pipewire=ON"
   ] ++ lib.optionals enableProprietaryCodecs [
     "-DQT_FEATURE_webengine_proprietary_codecs=ON"
@@ -241,7 +243,9 @@ qtModule {
 
     # Audio formats
     alsa-lib
+  ] ++ lib.optionals pulseaudioSupport [
     pulseaudio
+  ] ++ [
 
     # Text rendering
     fontconfig
@@ -265,8 +269,10 @@ qtModule {
     libXi
     xorg.libXext
 
+  ] ++ lib.optionals pipewireSupport [
     # Pipewire
     pipewire
+  ] ++ [
 
     libkrb5
     mesa
diff --git a/pkgs/development/libraries/qt-6/modules/qtwebsockets.nix b/pkgs/development/libraries/qt-6/modules/qtwebsockets.nix
index c3a346a8d78a6..eeff475f1eaff 100644
--- a/pkgs/development/libraries/qt-6/modules/qtwebsockets.nix
+++ b/pkgs/development/libraries/qt-6/modules/qtwebsockets.nix
@@ -1,11 +1,16 @@
-{ qtModule
+{ lib
+, stdenv
+, qtModule
 , qtbase
 , qtdeclarative
 , openssl
+, pkgsBuildHost
 }:
 
 qtModule {
   pname = "qtwebsockets";
   propagatedBuildInputs = [ qtbase qtdeclarative ];
   buildInputs = [ openssl ];
+  nativeQtBuildInputs = [ "qtdeclarative" ];
 }
+
diff --git a/pkgs/development/libraries/qt-6/qtModule.nix b/pkgs/development/libraries/qt-6/qtModule.nix
index 5434be84fa595..36ba2a382bc1b 100644
--- a/pkgs/development/libraries/qt-6/qtModule.nix
+++ b/pkgs/development/libraries/qt-6/qtModule.nix
@@ -6,6 +6,7 @@
 , moveBuildTree
 , srcs
 , patches ? [ ]
+, pkgsBuildHost
 }:
 
 args:
@@ -15,7 +16,7 @@ let
   version = args.version or srcs.${pname}.version;
   src = args.src or srcs.${pname}.src;
 in
-stdenv.mkDerivation (args // {
+(stdenv.mkDerivation ((builtins.removeAttrs args [ "dontIgnorePath" "nativeQtBuildInputs" ]) // {
   inherit pname version src;
   patches = args.patches or patches.${pname} or [ ];
 
@@ -39,4 +40,32 @@ stdenv.mkDerivation (args // {
     maintainers = with maintainers; [ milahu nickcao ];
     platforms = platforms.unix;
   } // (args.meta or { });
-})
+}))
+  .overrideAttrs(previousAttrs: lib.optionalAttrs (stdenv.buildPlatform != stdenv.hostPlatform) {
+    strictDeps = true;
+    env = (previousAttrs.env or {}) // { QT_HOST_PATH = "${pkgsBuildHost.qt6Packages.qtbase}"; };
+    cmakeFlags = [
+      "-DQT_FORCE_BUILD_TOOLS=true"
+    ] ++ lib.optionals (!(args.dontIgnorePath or false)) [
+      # When cross-compiling, QT's build process will ignore the
+      # $PATH, assuming a conventional FHS distro, all QT packages
+      # smashed together into a single installation directory, and
+      # poor hygiene on the part of the developer.  Since we carefully
+      # manage our $PATH and install each package to a separate prefix
+      # it's okay for QT to trust the $PATH we expose to it.
+      #
+      # The bizzarrely-named
+      # `QT_DISABLE_NO_DEFAULT_PATH_IN_QT_PACKAGES` option is how you
+      # tell QT that we are smarter than it is.
+      #
+      # See: https://codereview.qt-project.org/gitweb?p=qt%2Fqtbase.git;a=commit;h=7bb91398f25cb2016c0558fd397b376f413e3e96
+      # TODO: set this globally, everywhere.
+      "-DQT_DISABLE_NO_DEFAULT_PATH_IN_QT_PACKAGES=true"
+    ] ++ lib.optional (args?nativeQtBuildInputs)
+      ("-DQT_ADDITIONAL_HOST_PACKAGES_PREFIX_PATH=${
+        lib.concatMapStringsSep ":"
+          (pname: pkgsBuildHost.qt6Packages.${pname})
+          args.nativeQtBuildInputs}")
+    ++ (previousAttrs.cmakeFlags or []);
+  })
+
diff --git a/pkgs/development/python-modules/pyqt/6.x.nix b/pkgs/development/python-modules/pyqt/6.x.nix
index 51f0341703e18..f81dba1d0f529 100644
--- a/pkgs/development/python-modules/pyqt/6.x.nix
+++ b/pkgs/development/python-modules/pyqt/6.x.nix
@@ -19,8 +19,14 @@
 #, withConnectivity ? true
 , withPrintSupport ? true
 , cups
+, buildPackages
+, pkgsBuildTarget
+, pkgsHostTarget
+, pkgs
 }:
 
+assert withWebSockets;
+
 buildPythonPackage rec {
   pname = "PyQt6";
   version = "6.5.2";
@@ -40,6 +46,9 @@ buildPythonPackage rec {
     # ./pyqt5-fix-dbus-mainloop-support.patch
     # confirm license when installing via pyqt6_sip
     ./pyqt5-confirm-license.patch
+  ] ++ lib.optionals (stdenv.buildPlatform != stdenv.hostPlatform) [
+    # Adapted from Void Linux
+    ./pyproject-cross.patch
   ];
 
   # be more verbose
@@ -65,37 +74,36 @@ buildPythonPackage rec {
 
   dontWrapQtApps = true;
 
-  nativeBuildInputs = with qt6Packages; [
+  nativeBuildInputs = [
     pkg-config
     lndir
     sip
+    buildPackages.stdenv.cc.cc
+  ] ++ (with pkgsBuildTarget.targetPackages.qt6Packages; [
+    qmake
     qtbase
-    qtsvg
     qtdeclarative
     qtwebchannel
-    qmake
-    qtquick3d
-    qtquicktimeline
-  ]
-  # ++ lib.optional withConnectivity qtconnectivity
-  ++ lib.optional withMultimedia qtmultimedia
-  ++ lib.optional withWebSockets qtwebsockets
-  ++ lib.optional withLocation qtlocation
-  ;
+  ]);
 
-  buildInputs = with qt6Packages; [
+  buildInputs = lib.optionals dbusSupport [
     dbus
+  ] ++ (with qt6Packages; [
     qtbase
+    qtbase.dev
     qtsvg
     qtdeclarative
     pyqt-builder
     qtquick3d
+    qtwebchannel
+    qtwebchannel.dev
     qtquicktimeline
   ]
   # ++ lib.optional withConnectivity qtconnectivity
+  ++ lib.optional withMultimedia qtmultimedia
   ++ lib.optional withWebSockets qtwebsockets
   ++ lib.optional withLocation qtlocation
-  ;
+  );
 
   propagatedBuildInputs = [
     dbus-python
@@ -125,6 +133,7 @@ buildPythonPackage rec {
     "PyQt6.QtWidgets"
     "PyQt6.QtGui"
     "PyQt6.QtQuick"
+    "PyQt6.QtWebChannel"
   ]
   ++ lib.optional withWebSockets "PyQt6.QtWebSockets"
   ++ lib.optional withMultimedia "PyQt6.QtMultimedia"
@@ -132,8 +141,16 @@ buildPythonPackage rec {
   ++ lib.optional withLocation "PyQt6.QtPositioning"
   ;
 
-  # fix build with qt 6.6
-  env.NIX_CFLAGS_COMPILE = "-fpermissive";
+  env = {
+    NIX_CFLAGS_COMPILE = lib.concatStringsSep " " ([
+      # fix build with qt 6.6
+      "-fpermissive"
+    ] ++ lib.optionals (stdenv.buildPlatform != stdenv.hostPlatform) [
+      "-Wno-cast-function-type"
+    ]);
+  } // lib.optionalAttrs (stdenv.buildPlatform != stdenv.hostPlatform) {
+    EMULATOR = stdenv.hostPlatform.emulator buildPackages;
+  };
 
   meta = with lib; {
     description = "Python bindings for Qt6";
diff --git a/pkgs/development/python-modules/pyqt/pyproject-cross.patch b/pkgs/development/python-modules/pyqt/pyproject-cross.patch
new file mode 100644
index 0000000000000..75bd4300a3ed6
--- /dev/null
+++ b/pkgs/development/python-modules/pyqt/pyproject-cross.patch
@@ -0,0 +1,19 @@
+Index: PyQt6-6.1.0/project.py
+===================================================================
+--- PyQt6-6.1.0.orig/project.py
++++ PyQt6-6.1.0/project.py
+@@ -49,6 +49,14 @@ class PyQt(PyQtProject):
+         #   QtNfc, QtPositioning, QtLocation, QtRemoteObjects, QtSensors,
+         #   QtSerialPort, QtTextToSpeech, QtWebChannel, QtWebSockets
+ 
++    def run_command(self, args, *, fatal=True):
++        """ Run a command and display the output if requested. """
++        emulator = os.environ.get("EMULATOR")
++        builddir = os.environ.get("NIX_BUILD_TOP")
++        if emulator and args[0].startswith(builddir):
++            args.insert(0, emulator)
++        super().run_command(args, fatal=fatal)
++
+     def apply_user_defaults(self, tool):
+         """ Set default values where needed. """
+ 
diff --git a/pkgs/development/python-modules/pyqt6-webengine.nix b/pkgs/development/python-modules/pyqt6-webengine.nix
index d3b70a02f77dd..fe12b9d79085d 100644
--- a/pkgs/development/python-modules/pyqt6-webengine.nix
+++ b/pkgs/development/python-modules/pyqt6-webengine.nix
@@ -8,7 +8,12 @@
 , qt6Packages
 , pythonOlder
 , pyqt6
+, pyqt6-sip
+, setuptools
 , python
+, pkgsHostTarget
+, pkgsBuildTarget
+, buildPackages
 }:
 
 buildPythonPackage rec {
@@ -41,27 +46,38 @@ buildPythonPackage rec {
   # does not use the enableParallelBuilding flag
   postUnpack = ''
     export MAKEFLAGS+=" -j$NIX_BUILD_CORES"
+    export QT_ADDITIONAL_PACKAGES_PREFIX_PATH+="${qt6Packages.qtwebengine.dev}:${qt6Packages.qtwebengine}"
+    export QMAKEPATH+="${qt6Packages.qtwebengine.dev}:${qt6Packages.qtwebengine}"
   '';
 
   outputs = [ "out" "dev" ];
 
   dontWrapQtApps = true;
 
-  nativeBuildInputs = with qt6Packages; [
+  nativeBuildInputs = [
     pkg-config
     lndir
-    sip
-    qtwebengine
-    qmake
-    pyqt-builder
+    buildPackages.python3Packages.sip
+    pkgsHostTarget.qt6Packages.qtbase
+    pkgsHostTarget.qt6Packages.qmake
+    qt6Packages.qtbase
+    qt6Packages.qmake
   ];
 
   buildInputs = with qt6Packages; [
+    qtbase
+    qmake
+    qtdeclarative
     qtwebengine
+    qtwebengine.dev
+    pyqt6
+    pyqt6-sip
+    pyqt-builder
   ];
 
   propagatedBuildInputs = [
-    pyqt6
+    qt6Packages.qtbase
+    setuptools
   ];
 
   passthru = {