To use repos directly in your system execute these following commands (as root). Remember to change codename in step 2 to desired one
# wget -O - https://apt.kurwinet.pl/bofc-signing.pub.key | apt-key add - # echo "deb https://apt.kurwinet.pl/stretch/ stretch main" >> /etc/apt/sources.list # apt-get install apt-transport-https # apt-get update
These will: