pi@raspberrypi:~ $ ver=$(lsb_release -sr); if [ $ver != "18.04" -a $ver != "16.04" ]; then ver=18.04; fi
pi@raspberrypi:~ $ sudo sh -c "echo 'deb http://download.opensuse.org/repositories/home:/strycore/xUbuntu_18.04/ /' > /etc/apt/sources.list.d/home:strycore.list"
pi@raspberrypi:~ $ wget -q https://download.opensuse.org/repositories/home:/strycore/xUbuntu_$ver/Release.key -O- | sudo apt-key add -
OK
pi@raspberrypi:~ $ sudo apt-get update
Ign:1 http://download.opensuse.org/repositories/home:/strycore/xUbuntu_18.04  InRelease
Hit:2 http://archive.raspberrypi.org/debian stretch InRelease
Get:3 http://raspbian.raspberrypi.org/raspbian stretch InRelease [15.0 kB]
Ign:4 http://download.opensuse.org/repositories/home:/strycore/xUbuntu_18.04 ./ InRelease
Hit:5 http://download.opensuse.org/repositories/home:/strycore/xUbuntu_18.04  Release
Hit:6 http://download.opensuse.org/repositories/home:/strycore/xUbuntu_18.04 ./ Release
Get:7 http://raspbian.raspberrypi.org/raspbian stretch/main armhf Packages [11.7 MB]
Fetched 11.7 MB in 31s (376 kB/s)
Reading package lists... Done
pi@raspberrypi:~ $ sudo apt-get install lutris
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package lutris