duplicity falsely reports B2 python SDK not installed, fails backup to B2

[Noxy]

Description: Ubuntu 21.04
Release: 21.04

duplicity:
  Installed: 0.8.17-1build1
  Candidate: 0.8.17-1build1
  Version table:
 *** 0.8.17-1build1 500
        500 http://us.archive.ubuntu.com/ubuntu hirsute/main amd64 Packages
        100 /var/lib/dpkg/status

What I expected to happen: duplicity successfully backs up to B2 when I run `duplicity ~ b2://<redacted>@<redacted>`

What happened instead: duplicity immediately fails with the error "BackendException: B2 backend requires B2 Python SDK (pip install b2sdk)".

duplicity was working fine for me backing up my local machine to BackBlaze B2, when I was running 20.10. After upgrading to 21.04, now I get this problem.

Both b2 and b2sdk are installed by pip and pip3, with and without sudo. I do use pyenv to manage different Python versions but pyenv global is set to system when I use pip to try to troubleshoot this, so this should not be interfering

ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package: duplicity 0.8.17-1build1
ProcVersionSignature: Ubuntu 5.11.0-22.23-generic 5.11.21
Uname: Linux 5.11.0-22-generic x86_64
ApportVersion: 2.20.11-0ubuntu65.1
Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: Regolith:GNOME-Flashback:GNOME
Date: Thu Jun 24 12:28:50 2021
InstallationDate: Installed on 2020-11-20 (215 days ago)
InstallationMedia: Ubuntu 20.10 "Groovy Gorilla" - Release amd64 (20201022)
ProcEnviron:
 TERM=alacritty
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: duplicity
UpgradeStatus: Upgraded to hirsute on 2021-06-15 (8 days ago)

[Kenneth Loafman (kenneth-loafman)]

Two options for now:
- upgrade to the _latest_ (dev) version of duplicity,
- revert to b2sdk==1.7.0 until duplicity 0.8.20 is released

To revert do: _sudo pip install -U b2sdk==1.7.0_

There are multiple options for latest:

- Latest snap builds - “sudo snap install duplicity —classic —edge"
- Latest pip3 builds - “sudo pip3 install --pre duplicity"
- Latest duplicity PPA - https://code.launchpad.net/\~duplicity-team/+archive/ubuntu/duplicity-develop-git

Note 1: UNINSTALL duplicity first if it was installed from a different source..  This is due to divergent install locations, especially between repository installs and the other forms.

Note 2: Launchpad PPAs contain builds for Bionic 18.04, Eoan 19.10, Focal 20.04, Hirsute 20.10 and Impish 21.04.

Note 3: Xenial 16.04 works with Snap and Pip installs, but cannot be built under Launchpad PPAs at the moment.

[Noxy (noxypaws)]

Potentially a duplicate of https://bugs.launchpad.net/ubuntu/+source/duplicity/+bug/1743247 but I'm not ready to mark it as duplicate myself since I'm on a different release as that reporter

[Noxy (noxypaws)]

Even easier fix - instead of installing b2sdk via pip, installing python3-b2sdk via apt seems to have resolved this issue