DejaDup fails to launch back on Ubuntu 18.04

[Peter Thomson]

Recently upgraded to 18.04

Using deja-dup 37.1-2fakesync1
duplicity 0.7.17-0ubuntu1

Backup gets the following message:

Error processing remote manifest (duplicity-full.20180906T010419Z.manifest.gpg): GPG Failed, see log below:
===== Begin GnuPG log =====
gpg: WARNING: "--no-use-agent" is an obsolete option - it has no effect
gpg: AES encrypted data
gpg: encrypted with 1 passphrase
gpg: decryption failed: Bad session key
===== End GnuPG log =====

[johannes (j00hannes)]

I only get one error:

GPGError: GPG Failed, see log below:
===== Begin GnuPG log =====
gpg: WARNING: "--no-use-agent" is an obsolete option - it has no effect
===== End GnuPG log =====

[Michael Terry (mterry)]

I think this was due to a few bugs working in concert, causing situations where your backup chain was encrypted with two different passphrases. See the following wiki page to see if you are affected and how to recover.

https://wiki.gnome.org/Apps/DejaDup/PassphraseProblems2019

I will optimistically close this as “fixed in 39.1” but please reopen if you believe this to be caused by something else.

[Peter Thomson (pdt-emailme)]

I'm having a variant of this problem. Running check in terminal shows "wrong passphrase" against regular scheduled backups. Check in key folder shows passphrase used is correct. Check of backup folder files shows some backups performed even so. So sometimes passphrase used is correct, sometimes not.

Update of deja-dup fails to correct for this.