wget https://github.com/glennrp/libpng/archive/v1.2.59.tar.gz tar xvfz v1.2.59.tar.gz cd libpng-1.2.59/ ./configure make check sudo make install cp ./libpng-1.2.59/.libs/libpng12.so.0.59.0 ./lib/libpng12.so.0
sudo add-apt-repository ppa:rock-core/qt4 sudo sed -i 's/impish/focal/g' /etc/apt/sources.list.d/rock-core-ubuntu-qt4-impish.list sudo apt-get update sudo apt-get install libqtwebkit4