Comment 14 for bug 1412729

I just tested this in a VirtualBox VM (which contains a very "vanilla" 14.04 install with very few extra packages installed), and it didn't work.
I tried several times. The Epson repository is added successfully, but it hangs while it's installing the driver package (epson-inkjet-printer-nx420). The package is not installed.

The last output of "system-config-printer --debug" is:
  pk.refresh_cache succeeded
  pk.resolve
  pk.resolve succeeded
  package_id: epson-inkjet-printer-nx420;1.0.0-1lsb3.2;amd64;printdriver
  package not installed
  pk.install_packages
  Signature key supplied

After this, when I try to install the package manually, it fails because /var/cache/debconf/config.dat (and other files there) is locked by another process.
Here are the relevant lines (I think) of "ps aux":
  root 3331 0.0 0.0 0 0 pts/0 ZN+ 16:57 0:00 [dpkg] <defunct>
  root 3332 0.0 0.0 4444 648 pts/0 SN+ 16:57 0:00 /bin/sh -c /usr/sbin/dpkg-preconfigure --apt || true
  root 3333 0.0 1.0 64128 15628 pts/0 SN+ 16:57 0:00 /usr/bin/perl -w /usr/sbin/dpkg-preconfigure --apt
  root 3335 0.0 0.0 0 0 pts/0 ZN+ 16:57 0:00 [dpkg-preconfigu] <defunct>

However, if I install the packages "alien", "build-essential" and "lsb" before installing the printer through system-config-printer, the installation completes successfully.
Also, there was one time when apt failed to install the driver package (manually) because one of the dependencies, which was "lsb", was not properly configured.
So, is sytem-config-printer failing to configure a package (i.e. debconf), or is this a quirk with Virtualbox?

Another note. The driver installation window is too large to fit in my 1366x768 monitor, so the buttons in the bottom are not visible.