ubuntu-vm-builder hangs after bootstrapping (precise host, trusty guest)

[Marius Gedminas]

I'm running

  ubuntu-vm-builder kvm trusty \
    --libvirt qemu:///system \
    --tmpfs=2048 \
    --rootsize 20480 \
    --ssh-key=/root/.ssh/authorized_keys \
    --ssh-user-key=/root/.ssh/authorized_keys \
    --lock-user \
    --suite trusty \
    --components main,restricted,universe,multiverse \
    --addpkg openssh-server \
    --addpkg avahi-daemon \
    --addpkg vim \
    --addpkg git \
    --addpkg acpid \
    --addpkg unattended-upgrades \
    --addpkg command-not-found \
    --addpkg software-properties-common \
    --addpkg openjdk-7-jre-headless \
    --addpkg htop \
    --addpkg strace \
    --addpkg linux-image-generic \
    --hostname trusty64 \
    --domain lan \
    --bridge br0 \
    --mem 1024 --cpus 2

It outputs

  2015-05-29 12:43:06,265 INFO : Mounting tmpfs under /tmp/tmpJuZzghtmpfs
  2015-05-29 12:43:06,269 INFO : Calling hook: preflight_check
  2015-05-29 12:43:06,273 INFO : Calling hook: set_defaults
  2015-05-29 12:43:06,274 INFO : Calling hook: bootstrap

and then hangs.

pstree shows that ubuntu-vm-builder has one zombie child (debootstrap)

strace shows that ubuntu-vm-builder is waiting in select(5, [4], [], [], NULL)

lsof shows that fd 4 is a pipe that is shared between ubuntu-vm-builder and udevd, and by udevd I mean a 2nd copy of udevd that's running in the tmpfs.

/tmp/tmpJuZzghtmpfs/var/log/bootstrap.log mentions udev a few times:

  Selecting previously unselected package libudev1:amd64.
  dpkg: regarding .../libudev1_204-5ubuntu20_amd64.deb containing libudev1:amd64, pre-dependency problem:
   libudev1 pre-depends on multiarch-support
    multiarch-support is not installed.

  dpkg: warning: ignoring pre-dependency problem!
  Preparing to unpack .../libudev1_204-5ubuntu20_amd64.deb ...
  Unpacking libudev1:amd64 (204-5ubuntu20) ...
...
  Selecting previously unselected package udev.
  Preparing to unpack .../udev_204-5ubuntu20_amd64.deb ...
  Adding 'diversion of /bin/udevadm to /bin/udevadm.upgrade by fake-udev'
  Unpacking udev (204-5ubuntu20) ...
...
  Setting up udev (204-5ubuntu20) ...
   * Stopping the hotplug events dispatcher udevd

  Warning: Fake start-stop-daemon called, doing nothing
     ...done.
   * Starting the hotplug events dispatcher udevd
     ...done.
  Removing 'diversion of /bin/udevadm to /bin/udevadm.upgrade by fake-udev'

Manually killing this copy of udevd allows ubuntu-vm-builder to proceed.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: ubuntu-vm-builder 0.12.4+bzr477-0ubuntu5
ProcVersionSignature: Ubuntu 3.2.0-84.121-generic 3.2.68
Uname: Linux 3.2.0-84-generic x86_64
ApportVersion: 2.0.1-0ubuntu17.9
Architecture: amd64
Date: Fri May 29 12:58:00 2015
MarkForUpload: True
PackageArchitecture: all
ProcEnviron:
 LC_CTYPE=lt_LT.UTF-8
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: vm-builder
UpgradeStatus: Upgraded to precise on 2012-07-31 (1032 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.