debootstrap launches spurious udevd --daemon

On a 12.04 amd64 system, when running debootstrap to generate a 14.04 image [i386 or amd64], an instance of "udevd --daemon" is launched and persists after debootstrap terminates.

How to reproduce:

Freshly booted system. Before:

# ps www -C udevd
  PID TTY STAT TIME COMMAND
  449 ? Ss 0:00 /sbin/udevd --daemon
  673 ? S 0:00 /sbin/udevd --daemon
  674 ? S 0:00 /sbin/udevd --daemon

Now run the following:

# /usr/sbin/debootstrap --arch=i386 trusty /tmp/tmpBQAxhc http://archive.ubuntu.com/ubuntu

When it has finished:

# ps www -C udevd
  PID TTY STAT TIME COMMAND
  449 ? Ss 0:00 /sbin/udevd --daemon
  673 ? S 0:00 /sbin/udevd --daemon
  674 ? S 0:00 /sbin/udevd --daemon
29146 ? Ss 0:00 udevd --daemon

Extra tests:
This *doesn't* happen when building precise i386 on precise.
It *does* happen when building saucy i386 on precise.
It *doesn't* happen when building trusty i386 on trusty (tested in a trusty VM)

Apart from leaking a process, this is the root cause of bug #1287943: a process which runs debootstrap in a pipeline to read stdout finds that the pipeline is never closed (and therefore never terminates) until the udevd --daemon process is manually killed.

Most likely this is because stdout is passed to that process, which doesn't close it.

=== more details ===

Base system is 12.04 fully updated, with the raring enablement stack (kernel 3.8.0-42-generic). In a comment in #1287943 they asked me to include all the sources in /etc/apt/sources.list[.d] so here they are:

deb http://us.archive.ubuntu.com/ubuntu/ precise main restricted
deb-src http://us.archive.ubuntu.com/ubuntu/ precise main restricted

deb http://us.archive.ubuntu.com/ubuntu/ precise-updates main restricted
deb-src http://us.archive.ubuntu.com/ubuntu/ precise-updates main restricted

deb http://us.archive.ubuntu.com/ubuntu/ precise universe
deb-src http://us.archive.ubuntu.com/ubuntu/ precise universe
deb http://us.archive.ubuntu.com/ubuntu/ precise-updates universe
deb-src http://us.archive.ubuntu.com/ubuntu/ precise-updates universe

deb http://us.archive.ubuntu.com/ubuntu/ precise multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ precise multiverse
deb http://us.archive.ubuntu.com/ubuntu/ precise-updates multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ precise-updates multiverse

deb http://us.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse

deb http://security.ubuntu.com/ubuntu precise-security main restricted
deb-src http://security.ubuntu.com/ubuntu precise-security main restricted
deb http://security.ubuntu.com/ubuntu precise-security universe
deb-src http://security.ubuntu.com/ubuntu precise-security universe
deb http://security.ubuntu.com/ubuntu precise-security multiverse
deb-src http://security.ubuntu.com/ubuntu precise-security multiverse

deb http://archive.ubuntu.com/ubuntu/ precise-proposed restricted main multiverse universe
# but pinned so that no packages are taken from this repo, except python-vm-builder

deb http://ppa.launchpad.net/pkg-ganeti-devel/lts/ubuntu precise main
deb-src http://ppa.launchpad.net/pkg-ganeti-devel/lts/ubuntu precise main
deb http://ppa.launchpad.net/gns3/ppa/ubuntu precise main
deb-src http://ppa.launchpad.net/gns3/ppa/ubuntu precise main
deb http://ppa.launchpad.net/mactel-support/ppa/ubuntu precise main
deb http://ppa.launchpad.net/rquillo/ansible/ubuntu precise main
deb-src http://ppa.launchpad.net/rquillo/ansible/ubuntu precise main
deb http://www.ubnt.com/downloads/unifi/distros/deb/ubuntu ubuntu ubiquiti

deb http://ppa.launchpad.net/zfs-native/stable/ubuntu precise main
deb-src http://ppa.launchpad.net/zfs-native/stable/ubuntu precise main
# No zfs packages currently installed

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: debootstrap 1.0.40~ubuntu0.5
ProcVersionSignature: Ubuntu 3.8.0-42.62~precise1-generic 3.8.13.23
Uname: Linux 3.8.0-42-generic x86_64
ApportVersion: 2.0.1-0ubuntu17.6
Architecture: amd64
Date: Thu Jun 19 16:23:15 2014
InstallationMedia: Ubuntu-Server 12.04.3 LTS "Precise Pangolin" - Release amd64 (20130820.2)
MarkForUpload: True
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: debootstrap
UpgradeStatus: No upgrade log present (probably fresh install)