The Raspberry Pi Raspbian OS downloads are now Bullseye and Legacy (Buster). Bullseye doesn't support QT4 and the Legacy fails on ./configure checking for ICE and is missing the ICE development package. Going back to older versions of Buster and prior have a mode flag called OldStable and they will not update / upgrade. So currently I'm unable to build a working RPi 4 ShowEQ with the current Raspbian OS and version 6 of ShowEQ. There is a thread on ShowEQ7 supporting QT5 in development but until ShowEQ7 is available any suggestions on getting QT4 to work with Bullseye or how to find the ICE development library for the legacy buster version would be helpful.