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