The python package for qscintilla-qt5 contains pyqt5, so when you're using both they conflict: ``` Found duplicated packages in closure for dependency 'PyQt5': PyQt5 5.14.2 (/nix/store/viyh6yf9gjs4a55kyainh3d3vash3k0w-python3.7-PyQt5-5.14.2/lib/python3.7/site-packages) PyQt5 5.14.2 (/nix/store/bs29a9abcdkrk9damk8dac9zniagvljh-python3.7-qscintilla-2.11.2/lib/python3.7/site-packages) ```