package plymouth 0.9.2-3ubuntu9 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[LukeKendall]

Without me doing anything peculiar, my Ubuntu 14.04 system started pulling in packages from Xenial. 1st symptom was a broken dependency in plymouth. After a big apt-get update, many packages were broken.
Various packages were removed (like synaptic), and it was recommended that I re-installed 14.04.
Since I had found booting from a USB very problematic for the original install (on my Intel NUC), I instead tried an update-manager -d and approved the upgrade. After about an hour, with all required packages downloaded and about 50% of them installed, the system rebooted without warning while I was in the middle of working.
When it restarted it appeared to be half-installed, but wouldn't boot to a graphical UI. It said the plymouth package was broken.
I ran dpkg --configure -a, which seemed to install a lot of packages, though it complained that avahi-daemon, avahi-util, telepathy-salut, and account-plugin-salut were broken, at the end.
I tried rebooting and got the meaningless to a normal person error:
Error getting authority: Error initializing authority: Could not connect: No such file or directory (g-io-error-quark, 1)

Fortunately, google revealed that this means some stupid decision that unmountable drives should translate into a nonsense error and make it appear that the system is broken by refusing to boot. But adding the nofail option to non-essential drives in /etc/fstab should fix the problem, after a reboot. It did, but after login various errors popped up asking if I wished to report them.
This is one of them.

My impression is that Ubuntu has made a large leap backwards in reliability and usability. I gather the stupid decision to prevent a boot when some drives are unavailable is a design decision in systemd. If true, that is an astonishingly bad choice.

The bizarre error message and opaque error message "Error getting authority..." could be used as an excellent example to support those people who argue that Linux is user unfriendly. It provides insufficient context to even guess what it might be referring to; and it contains the classic "No such file or directory" with the failure to actually name the full path of the file that's missing. Remarkable that design errors like that are still being coded in.

What does this have to do with the plymouth package? I have no idea. All I could provide in this bug report was context for what had happened. Hopefully the automatically-collected files will provide more useful information than I can, to diagnose the problem.

I see that I've installed 16.04. update-manager -d does not actually tell you that in advance.

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: plymouth 0.9.2-3ubuntu9
ProcVersionSignature: Ubuntu 4.3.0-5.16-generic 4.3.3
Uname: Linux 4.3.0-5-generic x86_64
ApportVersion: 2.19.3-0ubuntu3
Architecture: amd64
Date: Sun Jan 17 00:13:14 2016
DefaultPlymouth: /usr/share/plymouth/themes/ubuntu-logo/ubuntu-logo.plymouth
ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationDate: Installed on 2014-01-24 (722 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Alpha amd64 (20140123)
ProcCmdLine: BOOT_IMAGE=/vmlinuz-4.3.0-5-generic root=UUID=c3e55a79-8e13-4001-b7b4-d73cc05b2443 ro quiet splash
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.3.0-5-generic root=UUID=c3e55a79-8e13-4001-b7b4-d73cc05b2443 ro quiet splash
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1
 apt 1.1.10
SourcePackage: plymouth
TextPlymouth: /usr/share/plymouth/themes/ubuntu-text/ubuntu-text.plymouth
Title: package plymouth 0.9.2-3ubuntu9 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 09/18/2013
dmi.bios.vendor: Intel Corp.
dmi.bios.version: WYLPT10H.86A.0018.2013.0918.2135
dmi.board.name: D34010WYK
dmi.board.vendor: Intel Corporation
dmi.board.version: H14771-302
dmi.chassis.type: 3
dmi.modalias: dmi:bvnIntelCorp.:bvrWYLPT10H.86A.0018.2013.0918.2135:bd09/18/2013:svn:pn:pvr:rvnIntelCorporation:rnD34010WYK:rvrH14771-302:cvn:ct3:cvr:

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Alberto Salvia Novella (es20490446e)]

"update-manager -d" means "update to the development distribution"

[Alberto Salvia Novella (es20490446e)]

Sure that upgrading to a development release is a step backward in reliability 😛

[Mathew Hodson (mhodson)]

As reported the system was in a broken state before the upgrade. I don't think there is enough information to say what happened.