How to fix Duplicity B2 (Backblaze) error

Question

When running Duplicity to backup to B2 (Backblaze) it fails with the following error:

Attempt 1 failed. AttributeError: B2ProgressListener instance has no attribute '__exit__'
Attempt 2 failed. AttributeError: B2ProgressListener instance has no attribute '__exit__'
Attempt 3 failed. AttributeError: B2ProgressListener instance has no attribute '__exit__'
Attempt 4 failed. AttributeError: B2ProgressListener instance has no attribute '__exit__'
Giving up after 5 attempts. AttributeError: B2ProgressListener instance has no attribute '__exit__'

I run it with the following command line:

  duplicity ~ b2://account:key@bucket

There is an empty file created in the B2 bucket, so access to the cloud seems to be working. What is wrong with my setup?

Ubuntu is version 16.04. Python is version 2.7.12. Duplicity is version 0.7.17. b2 backend is 1.3.4.

Answer 1

should be fixed in duplicity 0.7.18 released yesterday

• Fixed bug #1785520 with patch from Chris Hunt
  • Fix for B2 version 1.3.4 just released

https://launchpad.net/duplicity/+milestone/0.7.18

..ede/duply.net

Answer 2

It turns out this is a known bug:

https://bugs.launchpad.net/duplicity/+bug/1785520