Comment 9 for bug 1825211

I was able to recreate this today by taking a stock cosmic lxc image, installing ubuntu-mate-desktop, and then upgrading to disco. Here's the DuplicateSignature from the crash:

== DuplicateSignature =================================
package:libvlc-bin:3.0.6-1
Setting up fontconfig (2.13.1-2ubuntu2) ...
Regenerating fonts cache... done.
dpkg: cycle found while processing triggers:
 chain of packages whose triggers are or may be responsible:
  bamfdaemon -> mime-support
 packages' pending triggers which are or may be unresolvable:
  libvlc-bin:amd64: /usr/lib/x86_64-linux-gnu/vlc/plugins
  dbus: /etc/dbus-1/system.d
  ca-certificates: update-ca-certificates
  gnome-icon-theme: /usr/share/icons/gnome
  libc-bin: ldconfig
  dictionaries-common: update-default-ispell: update-default-wordlist: aspell-autobuildhash
  hicolor-icon-theme: /usr/share/icons/hicolor
  initramfs-tools: update-initramfs
  mime-support: /usr/share/applications: /usr/lib/mime/packages
  bamfdaemon: /usr/share/applications
dpkg: error processing package libvlc-bin:amd64 (--configure):
 triggers looping, abandoned

I submitted bug 1828639 with details.