In order to continue the development on my Linux machine, it was necessary to:

1) Install the Arduino IDE

Download and unpack the Arduino IDE 1.8.2

https://www.arduino.cc/en/Main/Software

Read the installation guide, but before proceed to the installation it might be necessary to edit the installation script.

https://www.arduino.cc/en/Guide/Linux

If you get errors during installation try this:

Edit the install.sh script and edit the following line:

RESOURCE_NAME=cc.arduino.arduinoide 

RESOURCE_NAME=arduino-arduinoide

then run the ./install script (note: without sudo!!)

2) Install the Digispark support add-on

https://digistump.com/wiki/digispark/tutorials/connecting

3) Create a udev rule to allow the micronucleus bootloader to work without being root.

https://github.com/micronucleus/micronucleus/wiki/Ubuntu-Linux

This file shall be created as a root. In Ubuntu:

sudo mousepad /etc/udev/rules.d/49-micronucleus.rules

mousepad is the name of the text editor. Can be either gedit, vi, emacs, etc...