content/hints/deja-dup.rst

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   2 A workaround for running deja-dup as root in Ubuntu 20.04
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   4
   5 :date: 2020-07-13
   6 :tags: hint, deja-dup, ubuntu
   7 :category: hints
   8 :author: Jude N
   9
  10 I found a workaround for the `Duplicity fails to start`_ issue where :code:`'sudo deja-dup'` would fail with the python stacktrace mentioned in the launchpad ticket.
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  12 The ticket was not very useful, so I started looking at the various files in the stacktrace and saw line from /usr/lib/python3/dist-packages/duplicity/backends/giobackend.py was within an :code:`"if u'DBUS_SESSION_BUS_ADDRESS' not in os.environ"` block.
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  14 So I wondered what would happen if I let that environment variable pass into the sudo environment.  I tried :code:`'sudo -E deja-dup'` as per `preserve the environment`_.  This didn't result in a stacktrace, but it ended up running the backup as the normal non-root user, probably because the preserved environment included the USER and HOME variables along with the DBUS_SESSION_BUS_ADDRESS variable.
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  16 Then I tried preserving just DBUS_SESSION_BUS_ADDRESS with :code:`'sudo --preserve-env=DBUS_SESSION_BUS_ADDRESS deja-dup'`, it worked as expected.
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  18 So the hint here is that when presented with a stacktrace don't be afraid to "Use the Source, Jean Luc".
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  20 .. image:: {static}/images/use-the-source-jean-luc.png
  21     :align: center
  22     :alt: A image of Patrick Stewart playing Gurney Halleck from David Lynch's Dune film, with the meme text 'Use the Source, Jean Luc'.
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  24
  25 .. _Duplicity fails to start: https://bugs.launchpad.net/ubuntu/+source/duplicity/+bug/1855736
  26 .. _preserve the environment: https://www.petefreitag.com/item/877.cfm