Manual Install: Force Python 3 version?

What is the problem?

I ended up with rasperian and the Python 2.7 version of Octoprint. I am trying to switch over to the Python 3 version.

What did you already try to solve it?

  1. I entered my virtual environment to uninstall the old octoprint with pip. Uninstall succeeded.
  2. I followed these instructions to set up Python 3.8, although I did not use step 6 to create an alias.
  3. I used "update-alternatives" to cause Python 3.8 to be the default version with the command below:
  4. update-alternatives --install /usr/bin/python python /usr/local/bin/python3.8 3
  5. I followed the instructions under "Installing manually" from here: OctoPrint.org - Download & Setup OctoPrint
    1. virtualenv OctoPrint
2. Installing OctoPrint  *into that virtual environment* :  `OctoPrint/bin/pip install OctoPrint`
3. OctoPrint may then be started through  `./OctoPrint/bin/octoprint serve`  or with an absolute path  `/path/to/OctoPrint/bin/octoprint serve`

Complete Logs

pi@prusaPi:~/OctoPrintPy3/bin $ ./octoprint serve
2020-09-10 23:57:58,459 - octoprint.startup - INFO - ******************************************************************************
2020-09-10 23:57:58,461 - octoprint.startup - INFO - Starting OctoPrint 1.4.2
2020-09-10 23:57:58,461 - octoprint.startup - INFO - ******************************************************************************
2020-09-10 23:57:58,754 - octoprint.util.connectivity.connectivity_checker - INFO - Connectivity changed from offline to online
2020-09-10 23:57:58,769 - octoprint.util.connectivity.connectivity_checker - INFO - Connectivity state is currently: online
2020-09-10 23:57:58,770 - octoprint.util.connectivity.connectivity_checker - INFO - Connecting to 8.8.8.8:53 is working
2020-09-10 23:57:58,770 - octoprint.util.connectivity.connectivity_checker - INFO - Resolving octoprint.org is working
2020-09-10 23:57:59,164 - octoprint.startup - INFO - Blacklist processing done, adding 10 blacklisted plugin versions: roomtemp (any), GcodeEditor (0.1.1), GcodeEditor (0.2.0), GcodeEditor (0.2.1), GcodeEditor (0.2.2), GcodeEditor (0.2.3), GcodeEditor (0.2.4), GcodeEditor (0.2.5), GcodeEditor (0.2.6), GcodeEditor (0.2.8)
2020-09-10 23:57:59,185 - octoprint.plugin.core - INFO - Loading plugins from /home/pi/OctoPrintPy3/lib/python2.7/site-packages/octoprint/plugins, /home/pi/.octoprint/plugins and installed plugin packages...
2020-09-10 23:57:59,823 - octoprint.plugins.octoprint.plugins.discovery - INFO - pybonjour is not installed, Zeroconf Discovery won't be available
2020-09-10 23:57:59,833 - octoprint.plugin.core - INFO - Found 18 plugin(s) providing 18 mixin implementations, 32 hook handlers
2020-09-10 23:57:59,981 - octoprint.server.heartbeat - INFO - Starting server heartbeat, 900.0s interval
2020-09-10 23:57:59,995 - octoprint.cli.server - ERROR - Uncaught exception
Traceback (most recent call last):
File "./octoprint", line 8, in
sys.exit(main())
File "/home/pi/OctoPrintPy3/local/lib/python2.7/site-packages/octoprint/init.py", line 629, in main
octo(args=args, prog_name="octoprint", auto_envvar_prefix="OCTOPRINT")
File "/home/pi/OctoPrintPy3/local/lib/python2.7/site-packages/click/core.py", line 829, in call
return self.main(*args, **kwargs)
File "/home/pi/OctoPrintPy3/local/lib/python2.7/site-packages/click/core.py", line 782, in main
rv = self.invoke(ctx)
File "/home/pi/OctoPrintPy3/local/lib/python2.7/site-packages/click/core.py", line 1259, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/home/pi/OctoPrintPy3/local/lib/python2.7/site-packages/click/core.py", line 1066, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/home/pi/OctoPrintPy3/local/lib/python2.7/site-packages/click/core.py", line 610, in invoke
return callback(*args, **kwargs)
File "/home/pi/OctoPrintPy3/local/lib/python2.7/site-packages/click/decorators.py", line 21, in new_func
return f(get_current_context(), *args, **kwargs)
File "/home/pi/OctoPrintPy3/local/lib/python2.7/site-packages/octoprint/cli/server.py", line 207, in serve_command
ignore_blacklist)
File "/home/pi/OctoPrintPy3/local/lib/python2.7/site-packages/octoprint/cli/server.py", line 119, in run_server
octoprint_server.run()
File "/home/pi/OctoPrintPy3/local/lib/python2.7/site-packages/octoprint/server/init.py", line 306, in run
self._start_intermediary_server()
File "/home/pi/OctoPrintPy3/local/lib/python2.7/site-packages/octoprint/server/init.py", line 1891, in _start_intermediary_server
self._intermediary_server.server_bind()
File "/usr/lib/python2.7/BaseHTTPServer.py", line 108, in server_bind
SocketServer.TCPServer.server_bind(self)
File "/usr/lib/python2.7/SocketServer.py", line 434, in server_bind
self.socket.bind(self.server_address)
File "/usr/lib/python2.7/socket.py", line 228, in meth
return getattr(self._sock,name)(*args)
error: [Errno 98] Address already in use

WRITE HERE

Additional information about your setup

When the virtual environment is active,
OctoPrint version is reported as 1.4.2
cat /etc/os-release reports back: "Raspbian GNU/Linux 10 (buster)"