Comment 3 for bug 1615238

Same story here:

Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-=============================================-===========================-===========================-===============================================================================================
ii deja-dup 34.2-0ubuntu1 amd64 Back up your files
ii deja-dup-backend-gvfs 34.2-0ubuntu1 all Remote server support for Déjà Dup
ii duplicity 0.7.06-2ubuntu2 amd64 encrypted bandwidth-efficient backup

as "deja-dup --backup" works well from the Terminal for me, I assume it might be something in Python pathes system-wide

Sergey