In case it matters, here are the repos being used for the Tinkerboard.
$ cat /etc/apt/sources.list
deb http://http.debian.net/debian/ stretch main contrib non-free
deb-src http://http.debian.net/debian/ stretch main contrib non-free
deb http://security.debian.org/ stretch/updates main contrib non-free
deb-src http://security.debian.org/ stretch/updates main contrib non-free
deb http://http.debian.net/debian/ stretch-updates main contrib non-free
deb-src http://http.debian.net/debian/ stretch-updates main contrib non-free
deb http://tprd.asus.com:8000 stretch main contrib non-free
deb-src http://tprd.asus.com:8000 stretch main contrib non-free
