Dear maintainer, I was able to launch the filter design tool manually, and here is the error message: "Please install PyQt4 to run this script (http://www.riverbankcomputing.co.uk/software/pyqt/download)".
It seems that this is only a dependency problem: gnuradio in Stretch has a dependency on python-qt4, but this dependency was dropped in the Buster version of the package. Would it be possible to add it? Regards, Thomas
