Michael,

Here's what I do in Linux Mint (based on and compatible with Ubuntu)

In the terminal execute the following

sudo apt-add-repository ppa:dansmith/chirp-snapshots
sudo apt-get update
sudo apt-get install chirp-daily

Then still in terminal add your user to the "dialout" group (substitute your Ubuntu username for {username})

sudo usermod -a -G dialout {username}

Then logout and login for the group membership change to take effect.

Jim KC9HI