Trying to install android-file-transfer Ubuntu 18.04 Bionic

There is a problem with the packaging of the PPA for Bionic. You can instead use Artful PPA to install Android File Transfer on Ubuntu 18.04. (Same version, 3.2-1 as of the time of writing)

First add the PPA to your sources:

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 0BB4A1B2FA1A38EB
sudo add-apt-repository "deb http://ppa.launchpad.net/samoilov-lex/aftl-stable/ubuntu artful main"

Make sure to run a sudo apt update to load the new packages, then install android-file-transfer the usual way:

sudo apt install android-file-transfer

The following steps were required before I finally got this to run:

1. Plug in phone via USB cable.
2. (on Android device) yes allow access.
3. (on Ubuntu) click 'eject' to unmount the Nautilus (file explorer) automount of the device.
4. Run sudo pkill mtp
5. Run android-file-transfer