Upgrading to Xenial leaves empty /usr/lib/x86_64-linux-gnu/pango/ hierarchy

[Christian Reis]

During an upgrade from a Trusty system to Xenial, I ended up with the following problem:

Removing linux-image-extra-3.13.0-85-generic (3.13.0-85.129) ...
depmod: FATAL: could not load /boot/System.map-3.13.0-85-generic: No such file or directory
run-parts: executing /etc/kernel/postinst.d/apt-auto-removal 3.13.0-85-generic /boot/vmlinuz-3.13.0-85-generic
run-parts: executing /etc/kernel/postinst.d/initramfs-tools 3.13.0-85-generic /boot/vmlinuz-3.13.0-85-generic
update-initramfs: Generating /boot/initrd.img-3.13.0-85-generic
WARNING: missing /lib/modules/3.13.0-85-generic
Ensure all necessary drivers are built into the linux image!
depmod: ERROR: could not open directory /lib/modules/3.13.0-85-generic: No such file or directory
depmod: FATAL: could not search modules: No such file or directory
cryptsetup: WARNING: failed to detect canonical device of /dev/nfs
cryptsetup: WARNING: could not determine root device from /etc/fstab
cp: cannot stat '/usr/lib/x86_64-linux-gnu/pango/1.6.0/module-files.d/libpango1.0-0.modules': No such file or directory
E: /usr/share/initramfs-tools/hooks/plymouth failed with return 1.
update-initramfs: failed for /boot/initrd.img-3.13.0-85-generic with 1.
run-parts: /etc/kernel/postinst.d/initramfs-tools exited with return code 1
dpkg: error processing package linux-image-extra-3.13.0-85-generic (--remove):
 subprocess installed post-removal script returned error exit status 1
Errors were encountered while processing:
 linux-image-extra-3.13.0-85-generic
E: Sub-process /usr/bin/dpkg returned an error code (1)

Turns out this was directly caused by simplistic checking in the plymouth initramfs-tools hook:

                # wheezy
                if ls /usr/lib/x86_64-linux-gnu/pango/1* > /dev/null 2>&1

I want back and checked a backup of my original Trusty filesystem, and it indeed has an empty hierarchy here:

  kiko@gasolinux:/usr/lib/x86_64-linux-gnu/pango$ ls -lR
  .:
  total 4
  drwxr-xr-x 3 root root 4096 Feb 26 2014 1.6.0/

  ./1.6.0:
  total 4
  drwxr-xr-x 2 root root 4096 Feb 27 2014 modules/

  ./1.6.0/modules:
  total 0

This may be better handled by smarter code in the plymouth hook, or if the empty directory may have further consequences, by making the pango upgrade really clean up that directory.

I solved the problem by removing the hierarchy and re-running apt-get -f install.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: libpango1.0-0 1.36.3-1ubuntu1.1
ProcVersionSignature: Ubuntu 3.13.0-87.133-generic 3.13.11-ckt39
Uname: Linux 3.13.0-87-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.21
Architecture: amd64
CurrentDesktop: Unity
Date: Sun Jun 5 20:45:27 2016
SourcePackage: pango1.0
UpgradeStatus: No upgrade log present (probably fresh install)

[Sebastien Bacher (seb128)]

seems similar to bug #1335017 which impacted trusty

[Sebastien Bacher (seb128)]

do you still have the upgrade log? it would have been useful to know what pango version was installed at the time of the issue...