Description of problem:
Updated to current s3ql on F22, attempted to unmount a mounted s3ql filesystem

Version-Release number of selected component:
s3ql-2.13-1.fc22

Additional info:
reporter:       libreport-2.6.0
cmdline:        /usr/bin/python3 /usr/bin/umount.s3ql /home/sten/.mnt/s3ql/sud0er-s3ql-rdiffbackup1
executable:     /usr/bin/umount.s3ql
kernel:         4.0.7-300.fc22.x86_64
runlevel:       N 5
type:           Python3
uid:            1000

Truncated backtrace:
__init__.py:839:resolve:pkg_resources.DistributionNotFound: The 'dugong>=3.4' distribution was not found and is required by s3ql

Traceback (most recent call last):
  File "/usr/lib/python3.4/site-packages/pkg_resources/__init__.py", line 651, in _build_master
    ws.require(__requires__)
  File "/usr/lib/python3.4/site-packages/pkg_resources/__init__.py", line 952, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/usr/lib/python3.4/site-packages/pkg_resources/__init__.py", line 844, in resolve
    raise VersionConflict(dist, req).with_context(dependent_req)
pkg_resources.ContextualVersionConflict: (dugong 3.3 (/usr/lib/python3.4/site-packages), Requirement.parse('dugong>=3.4'), {'s3ql'})

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/bin/umount.s3ql", line 5, in <module>
    from pkg_resources import load_entry_point
  File "/usr/lib/python3.4/site-packages/pkg_resources/__init__.py", line 3084, in <module>
    @_call_aside
  File "/usr/lib/python3.4/site-packages/pkg_resources/__init__.py", line 3070, in _call_aside
    f(*args, **kwargs)
  File "/usr/lib/python3.4/site-packages/pkg_resources/__init__.py", line 3097, in _initialize_master_working_set
    working_set = WorkingSet._build_master()
  File "/usr/lib/python3.4/site-packages/pkg_resources/__init__.py", line 653, in _build_master
    return cls._build_from_requirements(__requires__)
  File "/usr/lib/python3.4/site-packages/pkg_resources/__init__.py", line 666, in _build_from_requirements
    dists = ws.resolve(reqs, Environment())
  File "/usr/lib/python3.4/site-packages/pkg_resources/__init__.py", line 839, in resolve
    raise DistributionNotFound(req, requirers)
pkg_resources.DistributionNotFound: The 'dugong>=3.4' distribution was not found and is required by s3ql

Local variables in innermost frame:
req: Requirement.parse('dugong>=3.4')
processed: {Requirement.parse('s3ql==2.13'): True, Requirement.parse('llfuse>=0.39'): True}
new_requirements: []
installer: None
ws: <pkg_resources.WorkingSet object at 0x7f46e2b86c50>
env: <pkg_resources.Environment object at 0x7f46e2b86da0>
best: {'dugong': None, 'llfuse': llfuse 0.40 (/usr/lib64/python3.4/site-packages), 's3ql': s3ql 2.13 (/usr/lib64/python3.4/site-packages)}
replace_conflicting: False
requirements: [Requirement.parse('defusedxml'), Requirement.parse('requests'), Requirement.parse('pycrypto'), Requirement.parse('apsw>=3.7.0')]
required_by: defaultdict(<class 'set'>, {Requirement.parse('pycrypto'): {'s3ql'}, Requirement.parse('defusedxml'): {'s3ql'}, Requirement.parse('llfuse>=0.39'): {'s3ql'}, Requirement.parse('dugong>=3.4'): {'s3ql'}, Requirement.parse('apsw>=3.7.0'): {'s3ql'}, Requirement.parse('requests'): {'s3ql'}})
dist: None
requirers: {'s3ql'}
new_requirement: Requirement.parse('apsw>=3.7.0')
self: <pkg_resources.WorkingSet object at 0x7f46e2b86c50>
to_activate: [s3ql 2.13 (/usr/lib64/python3.4/site-packages), llfuse 0.40 (/usr/lib64/python3.4/site-packages)]