Comment 0 for bug 1732026

This system uses a btrfs filesystem in combination with snapper.

Via the file ``/etc/apt/apt.conf.d/80snapper`` (default file from repositories) it is configured to take pre-post snapshots upon performing any apt driven changes.

When using the update-manager i noticed 2 pre-snapshots are created at approximately the same time when upgrading. Leading to a snapper warning ``THROW: illegal snapshot`` for post upgrade actions.

In order to rule out ``snapper`` or ``apt`` as a source i tested the other methods (known to me) for upgrading packages, none of them showing the error (see table below):

================ ==================
Case # of pre snapshots
================ ==================
Synaptic updates 1
Update Manager 2 <-
apt upgrade 1
apt-get upgrade 1
================ ==================

I suspect the upgrade-manager makes 2 DPkg::Pre-Invoke calls when this happens. But i'm too unfamiliar with this package to do any real bug hunting.

ProblemType: Bug
DistroRelease: Ubuntu 17.04
Package: update-manager 1:17.04.8
ProcVersionSignature: Ubuntu 4.10.0-38.42-generic 4.10.17
Uname: Linux 4.10.0-38-generic x86_64
ApportVersion: 2.20.4-0ubuntu4.5
Architecture: amd64
CurrentDesktop: XFCE
Date: Mon Nov 13 22:41:48 2017
GsettingsChanges:
 b'com.ubuntu.update-manager' b'show-details' b'true'
 b'com.ubuntu.update-manager' b'window-height' b'1390'
 b'com.ubuntu.update-manager' b'first-run' b'false'
 b'com.ubuntu.update-manager' b'window-width' b'2560'
 b'com.ubuntu.update-manager' b'launch-time' b'int64 1510607283'
InstallationDate: Installed on 2016-12-21 (327 days ago)
InstallationMedia: Xubuntu 16.10 "Yakkety Yak" - Release amd64 (20161012.2)
PackageArchitecture: all
SourcePackage: update-manager
UpgradeStatus: Upgraded to zesty on 2017-04-16 (211 days ago)