deb http://debug.mirrors.debian.org/debian-debug stretch-debug main contrib non-free deb http://debug.mirrors.debian.org/debian-debug stretch-proposed-updates-debug main contrib non-free deb http://debug.mirrors.debian.org/debian-debug stretch-backports-debug main contrib non-free deb http://debug.mirrors.debian.org/debian-debug stretch-backports-sloppy-debug main contrib non-free