I followed the note "If you want to migrate your existing OctoPrint install..."
First, I made a backup and downloaded it to my desktop.
Second, I executed "sudo service octoprint stop"
Third, I executed the following:
mv ~/oprint ~/oprint.py2 virtualenv --python=/usr/bin/python3 oprint source ~/oprint/bin/activate pip install "OctoPrint>=1.4.0rc1" sudo service octoprint restart
I then tried to open the web page and got a page "The OctoPrint server is currently not running". As suggested, I executed the command "ps -ef | grep -i octoprint | grep -i python". Nothing is returned.
~/.octoprint/logs/octoprint.log and executed 'sudo service octoprint start')
There is nothing in octoprint.log.
Obviously, I've done something wrong... Can anyone enlighten me (@foosel?)