Bug#762750: cdrom: automatic partitioning (with seperate /usr) in installer doesn't work for systemd

[Philip J Freeman <elektron@halo.nu>]

Package: cdrom
Severity: critical
Tags: d-i
Justification: breaks unrelated software

Dear Maintainer,

  After installing a new system using partman-auto with separate /usr
partition, systemd was directing me to the following URL:

http://freedesktop.org/wiki/Software/systemd/separate-usr-is-broken/

I noticed this error while debugging the "default" network in libvirt
being broken. I'm unsure why it was broken, but moving the contents
of /usr onto the root filesystem and rebooting fixed the issue in libvirt
networking and made the error message go away.

-- System Information:
Debian Release: jessie/sid
  APT prefers testing-updates
  APT policy: (500, 'testing-updates'), (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 3.17.0-rc6 (SMP w/4 CPU cores; PREEMPT)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash