Update from 1.3.10 to 1.3.11 fails with Python Egg error

What is the problem?
Octoprint fails to update to 1.3.11 from the frontend and from command line.

First time posting here, so I'm trying to get the formatting right. Bear with me!

ERROR: Complete output from command python setup.py egg_info:
ERROR: /usr/lib/python2.7/distutils/dist.py:267: UserWarning: Unknown distribution option: 'project_urls'
warnings.warn(msg)
/usr/lib/python2.7/distutils/dist.py:267: UserWarning: Unknown distribution option: 'long_description_content_type'
warnings.warn(msg)
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/tmp/pip-req-build-r9_NrW/setup.py", line 231, in <module>
setup(**params())
File "/usr/lib/python2.7/distutils/core.py", line 111, in setup
_setup_distribution = dist = klass(attrs)
File "/home/pi/oprint/local/lib/python2.7/site-packages/setuptools/dist.py", line 266, in __init__
_Distribution.__init__(self,attrs)
File "/usr/lib/python2.7/distutils/dist.py", line 287, in __init__
self.finalize_options()
File "/home/pi/oprint/local/lib/python2.7/site-packages/setuptools/dist.py", line 301, in finalize_options
ep.load()(self, ep.name, value)
File "/home/pi/oprint/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2291, in load
return self.resolve()
File "/home/pi/oprint/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2301, in resolve
raise ImportError(str(exc))
ImportError: 'module' object has no attribute 'check_specifier'
----------------------------------------
ERROR: Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-req-build-r9_NrW/
The update did not finish successfully. Please consult <code>octoprint.log</code> and <code>plugin_softwareupdate_console.log</code> for details.

What did you already try to solve it?
Ran apt-get update/upgrade. Updated PIP. Disabled VPN & PiHole.

Logs (octoprint.log, serial.log or output on terminal tab, ...)

octoprint.log

UpdateError
2019-06-18 11:48:45,442 - octoprint.plugins.excluderegion - INFO - Event received: event=plugin_softwareupdate_update_failed payload={'to_version': '1.3.11', 'from_version': '1.3.10', 'target': 'octoprint'}
2019-06-18 12:00:10,001 - octoprint.server.heartbeat - INFO - Server heartbeat <3
2019-06-18 12:02:27,843 - octoprint.plugins.softwareupdate - INFO - Starting update of octoprint to 1.3.11...
2019-06-18 12:02:46,565 - octoprint.plugins.softwareupdate - ERROR - Update of octoprint can not be performed, please also check plugin_softwareupdate_console.log for possible causes of this
Traceback (most recent call last):
  File "/home/pi/oprint/lib/python2.7/site-packages/octoprint/plugins/softwareupdate/__init__.py", line 969, in _perform_update
    update_result = updater.perform_update(target, populated_check, target_version, log_cb=self._log, online=online)
  File "/home/pi/oprint/lib/python2.7/site-packages/octoprint/plugins/softwareupdate/updaters/pip.py", line 116, in perform_update
    raise exceptions.UpdateError("Error while executing pip install", (stdout, stderr))
UpdateError
2019-06-18 12:02:46,569 - octoprint.plugins.excluderegion - INFO - Event received: event=plugin_softwareupdate_update_failed payload={'to_version': '1.3.11', 'from_version': '1.3.10', 'target': 'octoprint'}
2019-06-18 12:02:55,610 - octoprint.plugins.softwareupdate - INFO - Starting update of octoprint to 1.3.11...
2019-06-18 12:03:14,979 - octoprint.plugins.softwareupdate - ERROR - Update of octoprint can not be performed, please also check plugin_softwareupdate_console.log for possible causes of this
Traceback (most recent call last):
  File "/home/pi/oprint/lib/python2.7/site-packages/octoprint/plugins/softwareupdate/__init__.py", line 969, in _perform_update
    update_result = updater.perform_update(target, populated_check, target_version, log_cb=self._log, online=online)
  File "/home/pi/oprint/lib/python2.7/site-packages/octoprint/plugins/softwareupdate/updaters/pip.py", line 116, in perform_update
    raise exceptions.UpdateError("Error while executing pip install", (stdout, stderr))
UpdateError
2019-06-18 12:03:14,989 - octoprint.plugins.excluderegion - INFO - Event received: event=plugin_softwareupdate_update_failed payload={'to_version': '1.3.11', 'from_version': '1.3.10', 'target': 'octoprint'}

plugin_softwareupdate_console.log

2019-06-18 12:02:27,859   /home/pi/oprint/bin/python -m pip install https://github.com/foosel/OctoPrint/archive/1.3.11.zip --no-cache-dir
2019-06-18 12:02:32,405 ! DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 won't be maintained after that date. A future version of pip will drop support for Python 2.7.
2019-06-18 12:02:33,225 > Looking in indexes: https://pypi.org/simple, https://www.piwheels.org/simple
2019-06-18 12:02:33,279 > Collecting https://github.com/foosel/OctoPrint/archive/1.3.11.zip
2019-06-18 12:02:35,284 > Downloading https://github.com/foosel/OctoPrint/archive/1.3.11.zip (5.4MB)
2019-06-18 12:02:43,478 ! ERROR: Complete output from command python setup.py egg_info:
2019-06-18 12:02:43,479 ! ERROR: /usr/lib/python2.7/distutils/dist.py:267: UserWarning: Unknown distribution option: 'project_urls'
2019-06-18 12:02:43,543 ! warnings.warn(msg)
2019-06-18 12:02:43,544 ! /usr/lib/python2.7/distutils/dist.py:267: UserWarning: Unknown distribution option: 'long_description_content_type'
2019-06-18 12:02:43,545 ! warnings.warn(msg)
2019-06-18 12:02:43,546 ! Traceback (most recent call last):
2019-06-18 12:02:43,547 ! File "<string>", line 1, in <module>
2019-06-18 12:02:43,548 ! File "/tmp/pip-req-build-fmDDva/setup.py", line 231, in <module>
2019-06-18 12:02:43,549 ! setup(**params())
2019-06-18 12:02:43,549 ! File "/usr/lib/python2.7/distutils/core.py", line 111, in setup
2019-06-18 12:02:43,550 ! _setup_distribution = dist = klass(attrs)
2019-06-18 12:02:43,551 ! File "/home/pi/oprint/local/lib/python2.7/site-packages/setuptools/dist.py", line 266, in __init__
2019-06-18 12:02:43,552 ! _Distribution.__init__(self,attrs)
2019-06-18 12:02:43,552 ! File "/usr/lib/python2.7/distutils/dist.py", line 287, in __init__
2019-06-18 12:02:43,553 ! self.finalize_options()
2019-06-18 12:02:43,554 ! File "/home/pi/oprint/local/lib/python2.7/site-packages/setuptools/dist.py", line 301, in finalize_options
2019-06-18 12:02:43,555 ! ep.load()(self, ep.name, value)
2019-06-18 12:02:43,556 ! File "/home/pi/oprint/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2291, in load
2019-06-18 12:02:43,556 ! return self.resolve()
2019-06-18 12:02:43,557 ! File "/home/pi/oprint/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2301, in resolve
2019-06-18 12:02:43,558 ! raise ImportError(str(exc))
2019-06-18 12:02:43,559 ! ImportError: 'module' object has no attribute 'check_specifier'
2019-06-18 12:02:43,559 ! ----------------------------------------
2019-06-18 12:02:43,560 ! ERROR: Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-req-build-fmDDva/
2019-06-18 12:02:55,624   /home/pi/oprint/bin/python -m pip install https://github.com/foosel/OctoPrint/archive/1.3.11.zip --no-cache-dir
2019-06-18 12:03:00,180 ! DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 won't be maintained after that date. A future version of pip will drop support for Python 2.7.
2019-06-18 12:03:01,049 > Looking in indexes: https://pypi.org/simple, https://www.piwheels.org/simple
2019-06-18 12:03:01,060 > Collecting https://github.com/foosel/OctoPrint/archive/1.3.11.zip
2019-06-18 12:03:02,072 > Downloading https://github.com/foosel/OctoPrint/archive/1.3.11.zip (5.4MB)
2019-06-18 12:03:10,587 ! ERROR: Complete output from command python setup.py egg_info:
2019-06-18 12:03:10,588 ! ERROR: /usr/lib/python2.7/distutils/dist.py:267: UserWarning: Unknown distribution option: 'project_urls'
2019-06-18 12:03:10,589 ! warnings.warn(msg)
2019-06-18 12:03:10,590 ! /usr/lib/python2.7/distutils/dist.py:267: UserWarning: Unknown distribution option: 'long_description_content_type'
2019-06-18 12:03:10,591 ! warnings.warn(msg)
2019-06-18 12:03:10,591 ! Traceback (most recent call last):
2019-06-18 12:03:10,592 ! File "<string>", line 1, in <module>
2019-06-18 12:03:10,593 ! File "/tmp/pip-req-build-r9_NrW/setup.py", line 231, in <module>
2019-06-18 12:03:10,593 ! setup(**params())
2019-06-18 12:03:10,594 ! File "/usr/lib/python2.7/distutils/core.py", line 111, in setup
2019-06-18 12:03:10,594 ! _setup_distribution = dist = klass(attrs)
2019-06-18 12:03:10,595 ! File "/home/pi/oprint/local/lib/python2.7/site-packages/setuptools/dist.py", line 266, in __init__
2019-06-18 12:03:10,596 ! _Distribution.__init__(self,attrs)
2019-06-18 12:03:10,596 ! File "/usr/lib/python2.7/distutils/dist.py", line 287, in __init__
2019-06-18 12:03:10,597 ! self.finalize_options()
2019-06-18 12:03:10,597 ! File "/home/pi/oprint/local/lib/python2.7/site-packages/setuptools/dist.py", line 301, in finalize_options
2019-06-18 12:03:10,598 ! ep.load()(self, ep.name, value)
2019-06-18 12:03:10,599 ! File "/home/pi/oprint/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2291, in load
2019-06-18 12:03:10,600 ! return self.resolve()
2019-06-18 12:03:10,601 ! File "/home/pi/oprint/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2301, in resolve
2019-06-18 12:03:10,601 ! raise ImportError(str(exc))
2019-06-18 12:03:10,602 ! ImportError: 'module' object has no attribute 'check_specifier'
2019-06-18 12:03:10,603 ! ----------------------------------------
2019-06-18 12:03:11,972 ! ERROR: Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-req-build-r9_NrW/

Additional information about your setup (OctoPrint version, OctoPi version, printer, firmware, ...)
OctoPrint version : 1.3.10
OctoPi version : 0.16.0
Running on Pi 3B+
Prusa Mk3S with MMU2S