Hi to all!
After upgrading to v72, when I visit the Backup Status page a window pops up with the messege: "Something is wrong with the backup: ", just like that. No error code or anything.
Can someone help me how to diagnose this issue?
Thank you in advance!!
Check journalctl -u mailinabox It might provide a hint.
Seeing failed backups here, too. Journal shows invalid password and logs "Mail-in-a-Box Management Daemon: Failed login attempt from ip … "
There were unattended upgrades to Duplicity and others yesterday:
Start-Date: 2025-06-19 19:10:09
Commandline: apt-get -y upgrade
Upgrade: linux-tools-common:amd64 (5.15.0-141.151, 5.15.0-142.152), duplicity:amd64 (3.0.4-ppa202502081832~ubuntu22.04.1, 3.0.5-ppa202506191602~ubuntu22.04.1), linux-libc-dev:amd64 (5.15.0-141.151, 5.15.0-142.152)
End-Date: 2025-06-19 19:10:18
This is likely the relevant error:
Fatal: reverse password verification check failed: Password mismatch
Hi !
Same problem on my system. The last successful backup was yesterday (16-06-2025)
journalctl -u mailinabox tells me the following:
Jun 20 02:17:38 box.oppers.eu start[64037]: Traceback (most recent call last):
Jun 20 02:17:38 box.oppers.eu start[64037]: File “/usr/bin/duplicity”, line 5, in
Jun 20 02:17:38 box.oppers.eu start[64037]: from duplicity.main import dup_run
Jun 20 02:17:38 box.oppers.eu start[64037]: ModuleNotFoundError: No module named ‘duplicity.main’
Something happened yesterday to cause this i guess. No idea what.
My system (ubuntu on a vps) is fully updated and patched and all that. Updates are installed every night (when available).
I read more people having this. Could it be some system or app update that did not play nice with miab? If so, how do i downgrade duplicity to yesterdays state?
I tried running the miab installer (i thought it might overwrite some things maybe), but that didn’t work.
pip install duplicity maybe? it looks like python doesn’t find that module
I have no idea and i really don’t want to mess with my box too much 
Probably duplicity has a bug in it’s release again. I recommend holding the duplicity package once this is resolved (apt-mark hold duplicity) I myself forgot to do that 
Since the v72 upgrade I’m getting this error when running backups:
Traceback (most recent call last):
File “/usr/bin/duplicity”, line 5, in
from duplicity.main import dup_run
ModuleNotFoundError: No module named ‘duplicity.main’
Something is wrong with the backup:
A similar message comes from checking duplicity version:
duplicity --version
Traceback (most recent call last):
File “/usr/bin/duplicity”, line 5, in
from duplicity.main import dup_run
ModuleNotFoundError: No module named ‘duplicity.main’
Hey guys as a temporary workaround - ‘apt remove duplicity’ and then cd to /var/cache/apt/archives/ and then ‘dpkg -i duplicity_3.0.4-ppa202502081832~ubuntu22.04.1_amd64.deb’ and last ‘apt-mark hold duplicity’ as KiekerJan suggests
I could not get a success with "dpkg -i duplicity_3.0.4-ppa202502081832~ubuntu22.04.1_amd64.deb’
However, this worked for me:
apt remove duplicity
snap install duplcity --classic
sudo ln -s /snap/bin/duplicity /usr/bin/duplicity
Backup ran fine after that.
I have fixed my 3 MIAB Servers as follows:
-
Download 3.0.4 version .deb from:
https://code.launchpad.net/~duplicity-team/+archive/ubuntu/duplicity-release-git/+files/duplicity_3.0.4-ppa202502081832~ubuntu22.04.1_amd64.deb -
FTP the .deb to your server home dir
-
run: sudo dpkg -i duplicity_3.0.4-ppa202502081832~ubuntu22.04.1_amd64.deb
-
sudo apt-mark hold duplicity
And sit back and wait for the replacement 3.0.5 PPA to come out.
2 Likes
May I suggest / lobby for a change for the MiaB installer? Seeing that duplicity is now a repeat offender (of automatically pushing update that breaks it), aren’t we better off having the installer hold duplicity by default and force a change to a known good version only during MiaB version upgrades that’s been tested against the specific version?
When your backup system fails at the wrong moment, as happenend to me this time round, it can get quite hairy.
As it turned out, it wasn’t the MiaB version upgrade that broke it, but the update of duplicity it triggered. For others it broke as a result of unattended updates.
I’m (reasonably) certain I checked that directory on my system and didn’t find that file there.
Plus the listing for 3.0.4 explicitly stated that it was removed from disk. I didn’t know about the +archive in the url to find it there. Good to know.
1 Like
I think that is a good plan. Based on the previous issues with duplicity i already keep it on hold. Feels like new release of duplicity are more beta than final versions.
Thanks that worked for me I was going crazy wondering why my server wasn’t backing up correctly in my home lab
I advocated for that back when duplicity blew up on me before. I got told to shut up about it. 
The stable snap release is the duplicity author’s preferred distribution channel and has been problem-free ever since I swapped. The biggest issue that has cropped up is a nuisance message about the python release being used by the snap release channel.
I downloaded and manually installed the 3.0.4 (as described higher up in the comments), and added /etc/apt/preferences.d/pin_duplicity.pref:
Explanation: Duplicity versions 3.0.1* and 3.0.5* have bugs and should not be installed
Package: duplicity
Pin: version 3.0.1*
Pin-Priority: -1
Package: duplicity
Pin: version 3.0.5*
Pin-Priority: -1
You have my vote for holding duplicity to a known and tested stable version.