duplicity fails with message: UnsupportedBackendScheme: scheme not supported in url

[Jan Skarvall]

After fresh installation of ubuntu 12.04.2 LTS server 64 bit version, my duplicity setup does not work anymore. The setup worked on ubuntu server 11.10 64 bit.

duplicity 0.6.18 now ends with the message:
Import of duplicity.backends.sshbackend Failed: No module named paramiko
Import of duplicity.backends.giobackend Failed: No module named gio
UnsupportedBackendScheme: scheme not supported in url: ssh://<email address hidden>/xxx

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: duplicity 0.6.18-0ubuntu3.1
ProcVersionSignature: Ubuntu 3.5.0-27.46~precise1-generic 3.5.7.7
Uname: Linux 3.5.0-27-generic x86_64
ApportVersion: 2.0.1-0ubuntu17.1
Architecture: amd64
Date: Tue Apr 16 10:05:43 2013
InstallationMedia: Ubuntu-Server 12.04.2 LTS "Precise Pangolin" - Release amd64 (20130214)
MarkForUpload: True
SourcePackage: duplicity
UpgradeStatus: No upgrade log present (probably fresh install)

[François Marier (fmarier)]

Are you sure the python-paramiko package is installed? It's an optional dependency of duplicity because it only needs it for ssh backends.

[Jan Skarvall (jan-skarvall)]

dpkg -l | grep python-paramiko returns nothing.
I certainly did not install python-paramiko on Ubuntu 11.10, and duplicity worked without problems using the same setup, i.e. running over ssh.

So I assumed that it should also work on 12.04, and that something changed in duplicity and there was a missing dependency in the duplicity package. That is why I reported the error.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Phill (phill.l)]

Confirmed in Ubuntu 16.04 LTS. Package `python-paramiko` must still be installed separately. If it's an optional plug-in then maybe having some `duplicity-xxxx` dummy packages would be useful with better error messages telling you what to install.