diff --git a/pkgs/development/libraries/qt-5/5.15/default.nix b/pkgs/development/libraries/qt-5/5.15/default.nix
index 5f82900903835..206691f607a32 100644
--- a/pkgs/development/libraries/qt-5/5.15/default.nix
+++ b/pkgs/development/libraries/qt-5/5.15/default.nix
@@ -207,6 +207,7 @@ let
         {
           inherit perl;
           inherit lib;
+          inherit buildPackages;
           # Use a variant of mkDerivation that does not include wrapQtApplications
           # to avoid cyclic dependencies between Qt modules.
           mkDerivation =
@@ -317,7 +318,7 @@ let
 
       qmake = makeSetupHook {
         name = "qmake-hook";
-        propagatedBuildInputs = [ self.qtbase.dev ];
+        depsTargetTargetPropagated = [ self.qtbase.dev ];
         substitutions = {
           inherit debug;
           fix_qmake_libtool = ../hooks/fix-qmake-libtool.sh;
@@ -326,7 +327,8 @@ let
 
       wrapQtAppsHook = makeSetupHook {
         name = "wrap-qt5-apps-hook";
-        propagatedBuildInputs = [ self.qtbase.dev buildPackages.makeBinaryWrapper ]
+        propagatedBuildInputs = [ buildPackages.makeBinaryWrapper ];
+        depsTargetTargetPropagated = [ self.qtbase.dev ]
           ++ lib.optional stdenv.isLinux self.qtwayland.dev;
       } ../hooks/wrap-qt-apps-hook.sh;
     } // lib.optionalAttrs config.allowAliases {
diff --git a/pkgs/development/libraries/qt-5/modules/qtbase.nix b/pkgs/development/libraries/qt-5/modules/qtbase.nix
index de73bcbe27724..4cf255e2c7399 100644
--- a/pkgs/development/libraries/qt-5/modules/qtbase.nix
+++ b/pkgs/development/libraries/qt-5/modules/qtbase.nix
@@ -28,6 +28,7 @@
 , developerBuild ? false
 , decryptSslTraffic ? false
 , testers
+, buildPackages
 }:
 
 let
@@ -82,6 +83,11 @@ stdenv.mkDerivation (finalAttrs: {
   nativeBuildInputs = [ bison flex gperf lndir perl pkg-config which ]
     ++ lib.optionals stdenv.isDarwin [ xcbuild ];
 
+  # `qtbase` expects to find `cc` (with no prefix) in the
+  # `$PATH`, so the following is needed even if
+  # `stdenv.buildPlatform.canExecute stdenv.hostPlatform`
+  depsBuildBuild = [ buildPackages.stdenv.cc ];
+
   propagatedNativeBuildInputs = [ lndir ];
 
   # libQt5Core links calls CoreFoundation APIs that call into the system ICU. Binaries linked
diff --git a/pkgs/development/libraries/qt-5/qtModule.nix b/pkgs/development/libraries/qt-5/qtModule.nix
index 9abd9fabc9576..67e2abfd0adb4 100644
--- a/pkgs/development/libraries/qt-5/qtModule.nix
+++ b/pkgs/development/libraries/qt-5/qtModule.nix
@@ -1,4 +1,6 @@
-{ lib, mkDerivation, perl }:
+{ lib, mkDerivation, perl
+, buildPackages
+}:
 
 let inherit (lib) licenses maintainers platforms; in
 
@@ -16,8 +18,10 @@ mkDerivation (args // {
   inherit pname version src;
   patches = (args.patches or []) ++ (patches.${pname} or []);
 
-  nativeBuildInputs = (args.nativeBuildInputs or []) ++ [ perl self.qmake ];
+  nativeBuildInputs = (args.nativeBuildInputs or []) ++ [ perl self.qmake self.qtbase.dev ];
+
   propagatedBuildInputs = args.qtInputs ++ (args.propagatedBuildInputs or []);
+  depsBuildBuild = [ buildPackages.stdenv.cc ];
 
   outputs = args.outputs or [ "out" "dev" ];
   setOutputFlags = args.setOutputFlags or false;
diff --git a/pkgs/development/python-modules/pyqt/5.x.nix b/pkgs/development/python-modules/pyqt/5.x.nix
index 6bb268d21995c..de33f61ef9aab 100644
--- a/pkgs/development/python-modules/pyqt/5.x.nix
+++ b/pkgs/development/python-modules/pyqt/5.x.nix
@@ -19,6 +19,7 @@
 , withLocation ? false
 , withSerialPort ? false
 , withTools ? false
+, pkgsBuildTarget
 }:
 
 buildPythonPackage rec {
@@ -55,6 +56,37 @@ buildPythonPackage rec {
     minimum-macos-version = "11.0"
   '' + ''
     EOF
+  ''
+
+  # pyqt-builder tries to compile *and run* these programs.  This
+  # is really sad because the only thing they do is print out a
+  # flag based on whether or not some compile-time symbol was
+  # defined.  This could all be done without having to *execute*
+  # cross-compiled programs!
+  #
+  # Here is the complete list of things checked:
+  #
+  # QT_NO_PRINTDIALOG                                                           => PyQt_PrintDialog
+  # QT_NO_PRINTER                                                               => PyQt_Printer
+  # QT_NO_PRINTPREVIEWDIALOG                                                    => PyQt_PrintPreviewDialog
+  # QT_NO_PRINTPREVIEWWIDGET                                                    => PyQt_PrintPreviewWidget
+  # QT_NO_SSL                                                                   => PyQt_SSL
+  # QT_SHARED || QT_DLL                                                         => shared (otherwise static)
+  # QT_NO_PROCESS                                                               => PyQt_Process
+  # QT_NO_FPU || Q_PROCESSOR_ARM || Q_OS_WINCE                                  => PyQt_qreal_double
+  # sizeof (qreal) != sizeof (double)                                           => PyQt_qreal_double
+  # !Q_COMPILER_CONSTEXPR !Q_COMPILER_UNIFORM_INIT                              => PyQt_CONSTEXPR
+  # QT_NO_ACCESSIBILITY                                                         => PyQt_Accessibility
+  # QT_NO_OPENGL                                                                => PyQt_OpenGL PyQt_Desktop_OpenGL
+  # defined(QT_OPENGL_ES) || defined(QT_OPENGL_ES_2) || defined(QT_OPENGL_ES_3) => PyQt_Desktop_OpenGL
+  # QT_NO_RAWFONT                                                               => PyQt_RawFont
+  # QT_NO_SESSIONMANAGER                                                        => PyQt_SessionManager
+  #
+  + lib.optionalString (!(stdenv.buildPlatform.canExecute stdenv.hostPlatform)) ''
+    rm config-tests/cfgtest_QtCore.cpp
+    rm config-tests/cfgtest_QtGui.cpp
+    rm config-tests/cfgtest_QtNetwork.cpp
+    rm config-tests/cfgtest_QtPrintSupport.cpp
   '';
 
   enableParallelBuilding = true;
@@ -72,12 +104,13 @@ buildPythonPackage rec {
 
   dontWrapQtApps = true;
 
-  nativeBuildInputs = with libsForQt5; [
+  nativeBuildInputs = (with libsForQt5; [
     pkg-config
     qmake
     setuptools
     lndir
     sip
+  ]) ++ (with pkgsBuildTarget.targetPackages.libsForQt5; [
     qtbase
     qtsvg
     qtdeclarative
@@ -90,7 +123,7 @@ buildPythonPackage rec {
     ++ lib.optional withLocation qtlocation
     ++ lib.optional withSerialPort qtserialport
     ++ lib.optional withTools qttools
-  ;
+  );
 
   buildInputs = with libsForQt5; [
     dbus
diff --git a/pkgs/misc/frescobaldi/default.nix b/pkgs/misc/frescobaldi/default.nix
index 57baeb7fe828f..5be22418a92f6 100644
--- a/pkgs/misc/frescobaldi/default.nix
+++ b/pkgs/misc/frescobaldi/default.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, buildPythonApplication, fetchFromGitHub, python3Packages, pyqtwebengine, lilypond }:
+{ lib, stdenv, buildPythonApplication, fetchFromGitHub, python3Packages, pyqtwebengine, lilypond, gettext }:
 
 buildPythonApplication rec {
   pname = "frescobaldi";
@@ -22,7 +22,7 @@ buildPythonApplication rec {
     pyqtwebengine
   ];
 
-  nativeBuildInputs = [ pyqtwebengine.wrapQtAppsHook ];
+  nativeBuildInputs = [ pyqtwebengine.wrapQtAppsHook gettext ];
 
   # Needed because source is fetched from git
   preBuild = ''