pythonPackages.qscintilla-qt5: add pythonImportsCheck and disable Python 2 support

pkgs/development/python-modules/qscintilla-qt5/default.nix

@@ -10,6 +10,8 @@ buildPythonPackage rec {
   src = qscintilla.src;
   format = "other";
 
+  disabled = !isPy3k;
+
   nativeBuildInputs = [ sip_4 qtbase ];
   buildInputs = [ qscintilla ];
   propagatedBuildInputs = [ pyqt5 ];
@@ -23,11 +25,6 @@ buildPythonPackage rec {
       "'$out/${python.sitePackages}'"
   '';
 
-  pyqt5_sip_dir = if isPy3k then
-    "${pyqt5}/${python.sitePackages}/PyQt5/bindings"
-  else
-    "${pyqt5}/share/sip/PyQt5";
-
   preConfigure = ''
     # configure.py will look for this folder
     mkdir -p $out/share/sip/PyQt5
@@ -43,11 +40,21 @@ buildPythonPackage rec {
       --qsci-incdir=${qscintilla}/include \
       --qsci-featuresdir=${qscintilla}/mkspecs/features \
       --qsci-libdir=${qscintilla}/lib \
-      --pyqt-sipdir=${pyqt5_sip_dir} \
+      --pyqt-sipdir=${pyqt5}/${python.sitePackages}/PyQt5/bindings \
       --qsci-sipdir=$out/share/sip/PyQt5 \
       --sip-incdir=${sip_4}/include
   '';
 
+  postInstall = ''
+    # Needed by pythonImportsCheck to find the module
+    export PYTHONPATH="$out/${python.sitePackages}:$PYTHONPATH"
+  '';
+
+  # Checked using pythonImportsCheck
+  doCheck = false;
+
+  pythonImportsCheck = [ "PyQt5.Qsci" ];
+
   meta = with lib; {
     description = "A Python binding to QScintilla, Qt based text editing control";
     license = licenses.lgpl21Plus;