Linux Mint 17.3
I resurect this post because i have the problem of missing /dev/ttyACM0 and read lot of pages without solution.
But finally I perform these (seeming irrelevant) steps, probably only the last 'restart' fix the port problem, but no way to check it.
(Arduino was tested OK on another PC)
- Install old version of Arduino 1:1.0.5 (from Linux Mint repos) (no change)
- Install a USB mem and format (Magic, or not)
sudo /etc/init.d/udev restart
and then the com port appears in the 'ports' list
Hope this help !