Control: tags -1 patch -D_Python_CONFIG:FILEPATH=/usr/bin/x86_64-linux-gnu-python3.7-config \ -DPython_EXECUTABLE:FILEPATH=/usr/bin/python3.7 \ should read: -D_Python_CONFIG:FILEPATH=/usr/bin/x86_64-linux-gnu-python3.8-config \ -DPython_EXECUTABLE:FILEPATH=/usr/bin/python3.8 \ Maybe double-check if PYTHON_PREFER_VERSION is a more robust alternative? Also make sure to update d/control: X-Python3-Version: 3.7 into X-Python3-Version: 3.8