ubuntu-vm-builder can't create VM with unclear reporting

[CTAC]

Trying to create virtual machine via ubuntu-vm-builder (as on https://help.ubuntu.com/community/KVM/CreateGuests)
and application crashes without any specific errors.

1. Ubuntu release:
$ lsb_release -rd
Description: Ubuntu 16.04.2 LTS
Release: 16.04

2. Package version:
ubuntu-vm-builder:
  Installed: 0.12.4+bzr494-0ubuntu1
  Candidate: 0.12.4+bzr494-0ubuntu1
  Version table:
 *** 0.12.4+bzr494-0ubuntu1 500
        500 http://cz.archive.ubuntu.com/ubuntu xenial/universe amd64 Packages
        500 http://cz.archive.ubuntu.com/ubuntu xenial/universe i386 Packages
        100 /var/lib/dpkg/status

3. expect that virtual machine should be created
4. LANG=C sudo ubuntu-vm-builder kvm xenial --mem=1024 --cpus=2 --libvirt qemu:///system
[sudo] password for ctac:
2017-07-12 13:38:01,571 INFO : logging to file: /tmp/tmpaK1jaj
2017-07-12 13:38:01,597 INFO : Calling hook: preflight_check
2017-07-12 13:38:01,599 INFO : Calling hook: set_defaults
2017-07-12 13:38:01,600 INFO : Calling hook: bootstrap
2017-07-12 13:39:47,482 INFO : Calling hook: configure_os
2017-07-12 13:39:56,372 INFO :
2017-07-12 13:39:56,372 INFO : Current default time zone: 'Etc/UTC'
2017-07-12 13:39:56,374 INFO : Local time is now: Wed Jul 12 11:39:56 UTC 2017.
2017-07-12 13:39:56,374 INFO : Universal Time is now: Wed Jul 12 11:39:56 UTC 2017.
2017-07-12 13:39:56,374 INFO :
2017-07-12 13:39:57,235 INFO : Generating locales (this might take a while)...
2017-07-12 13:39:57,246 INFO : Generation complete.
Extracting templates from packages: 100%
2017-07-12 13:40:30,024 INFO : W: --force-yes is deprecated, use one of the options starting with --allow instead.
2017-07-12 13:40:30,024 INFO : E: Sub-process /usr/bin/dpkg returned an error code (1)
2017-07-12 13:40:30,025 INFO : Cleaning up
2017-07-12 13:40:31,085 ERROR : Process (['chroot', '/tmp/tmpCkueJi', 'apt-get', '-y', '--force-yes', 'dist-upgrade']) returned 100. stdout: Reading package lists...
Building dependency tree...
Calculating upgrade...
The following packages will be upgraded:
  apt apt-utils base-files bash bsdutils console-setup console-setup-linux
  coreutils dh-python distro-info-data dpkg eject gcc-5-base gnupg gpgv grep
  ifupdown init init-system-helpers initramfs-tools initramfs-tools-bin
  initramfs-tools-core iproute2 isc-dhcp-client isc-dhcp-common kbd
  keyboard-configuration klibc-utils less libapparmor1 libapt-inst2.0
  libapt-pkg5.0 libblkid1 libc-bin libc6 libdns-export162 libexpat1 libfdisk1
  libgcrypt20 libgnutls-openssl27 libgnutls30 libhogweed4 libidn11
  libisc-export160 libklibc libmount1 libnettle6 libp11-kit0 libprocps4
  libpython3.5-minimal libpython3.5-stdlib libsmartcols1 libssl1.0.0
  libstdc++6 libsystemd0 libtasn1-6 libudev1 libuuid1 locales login logrotate
  lsb-base lsb-release makedev mount multiarch-support passwd procps python3.5
  python3.5-minimal resolvconf sudo systemd systemd-sysv tar tzdata udev
  util-linux vim-common vim-tiny zlib1g
81 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 33.9 MB of archives.
After this operation, 217 kB of additional disk space will be used.
Get:1 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 base-files amd64 9.4ubuntu4.4 [60.2 kB]
[...]
Preconfiguring packages ...
Fetched 33.9 MB in 15s (2195 kB/s)
(Reading database ... 10446 files and directories currently installed.)
Preparing to unpack .../base-files_9.4ubuntu4.4_amd64.deb ...
Unpacking base-files (9.4ubuntu4.4) over (9.4ubuntu4) ...
Setting up base-files (9.4ubuntu4.4) ...
[...]
Configuration file '/etc/sudoers'
 ==> Modified (by you or by a script) since installation.
 ==> Package distributor has shipped an updated version.
   What would you like to do about it ? Your options are:
    Y or I : install the package maintainer's version
    N or O : keep your currently-installed version
      D : show the differences between the versions
      Z : start a shell to examine the situation
 The default action is to keep your current version.
*** sudoers (Y/I/N/O/D/Z) [default=N] ? dpkg: error processing package sudo (--configure):
 end of file on stdin at conffile prompt
[...]
Processing triggers for resolvconf (1.78ubuntu4) ...
Errors were encountered while processing:
 sudo
Extracting templates from packages: 100%
W: --force-yes is deprecated, use one of the options starting with --allow instead.
E: Sub-process /usr/bin/dpkg returned an error code (1)

Traceback (most recent call last):
  File "/usr/bin/ubuntu-vm-builder", line 24, in <module>
    uvb.main()
  File "/usr/lib/python2.7/dist-packages/VMBuilder/contrib/cli.py", line 221, in main
    distro.build_chroot()
  File "/usr/lib/python2.7/dist-packages/VMBuilder/distro.py", line 84, in build_chroot
    self.call_hooks('configure_os')
  File "/usr/lib/python2.7/dist-packages/VMBuilder/distro.py", line 67, in call_hooks
    call_hooks(self, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/VMBuilder/util.py", line 170, in call_hooks
    getattr(context, func)(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/VMBuilder/plugins/ubuntu/distro.py", line 153, in configure_os
    self.suite.update()
  File "/usr/lib/python2.7/dist-packages/VMBuilder/plugins/ubuntu/dapper.py", line 76, in update
    env={ 'DEBIAN_FRONTEND' : 'noninteractive' })
  File "/usr/lib/python2.7/dist-packages/VMBuilder/plugins/ubuntu/dapper.py", line 331, in run_in_target
    return self.context.run_in_target(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/VMBuilder/plugins/__init__.py", line 86, in run_in_target
    return util.run_cmd('chroot', self.chroot_dir, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/VMBuilder/util.py", line 120, in run_cmd
    raise VMBuilderException, "Process (%s) returned %d. stdout: %s, stderr: %s" % (args.__repr__(), status, mystdout.buf, mystderr.buf)
VMBuilder.exception.VMBuilderException: Process (['chroot', '/tmp/tmpCkueJi', 'apt-get', '-y', '--force-yes', 'dist-upgrade']) returned 100. stdout: Reading package lists...
Building dependency tree...
Calculating upgrade...
The following packages will be upgraded:
  apt apt-utils base-files bash bsdutils console-setup console-setup-linux
  coreutils dh-python distro-info-data dpkg eject gcc-5-base gnupg gpgv grep
  ifupdown init init-system-helpers initramfs-tools initramfs-tools-bin
  initramfs-tools-core iproute2 isc-dhcp-client isc-dhcp-common kbd
  keyboard-configuration klibc-utils less libapparmor1 libapt-inst2.0
  libapt-pkg5.0 libblkid1 libc-bin libc6 libdns-export162 libexpat1 libfdisk1
  libgcrypt20 libgnutls-openssl27 libgnutls30 libhogweed4 libidn11
  libisc-export160 libklibc libmount1 libnettle6 libp11-kit0 libprocps4
  libpython3.5-minimal libpython3.5-stdlib libsmartcols1 libssl1.0.0
  libstdc++6 libsystemd0 libtasn1-6 libudev1 libuuid1 locales login logrotate
  lsb-base lsb-release makedev mount multiarch-support passwd procps python3.5
  python3.5-minimal resolvconf sudo systemd systemd-sysv tar tzdata udev
  util-linux vim-common vim-tiny zlib1g
81 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 33.9 MB of archives.
After this operation, 217 kB of additional disk space will be used.
Get:1 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 base-files amd64 9.4ubuntu4.4 [60.2 kB]
[...]
Preconfiguring packages ...
Fetched 33.9 MB in 15s (2195 kB/s)
(Reading database ... 10446 files and directories currently installed.)
Preparing to unpack .../base-files_9.4ubuntu4.4_amd64.deb ...
[...]
Setting up sudo (1.8.16-0ubuntu1.4) ...

Configuration file '/etc/sudoers'
 ==> Modified (by you or by a script) since installation.
 ==> Package distributor has shipped an updated version.
   What would you like to do about it ? Your options are:
    Y or I : install the package maintainer's version
    N or O : keep your currently-installed version
      D : show the differences between the versions
      Z : start a shell to examine the situation
 The default action is to keep your current version.
*** sudoers (Y/I/N/O/D/Z) [default=N] ? dpkg: error processing package sudo (--configure):
 end of file on stdin at conffile prompt
Setting up vim-common (2:7.4.1689-3ubuntu1.2) ...
[...]
Processing triggers for resolvconf (1.78ubuntu4) ...
Errors were encountered while processing:
 sudo
Extracting templates from packages: 100%
W: --force-yes is deprecated, use one of the options starting with --allow instead.
E: Sub-process /usr/bin/dpkg returned an error code (1)

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: ubuntu-vm-builder 0.12.4+bzr494-0ubuntu1
ProcVersionSignature: Ubuntu 4.8.0-58.63~16.04.1-generic 4.8.17
Uname: Linux 4.8.0-58-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.9
Architecture: amd64
Date: Wed Jul 12 13:14:02 2017
InstallationDate: Installed on 2017-07-06 (5 days ago)
InstallationMedia: Ubuntu 16.04.2 LTS "Xenial Xerus" - Release amd64 (20170215.2)
PackageArchitecture: all
SourcePackage: vm-builder
UpgradeStatus: No upgrade log present (probably fresh install)

[Christian Ehrhardt  (paelzer)]

Hi CTAC,
thanks for your report.

As in the other bug 1703822 you reported I'd ask you for now if you think you could work with uvtool-libvirt to get done what you need.

I've taken the task (https://trello.com/c/9F9wHGXp) to consider and decide the future of vmbuilder, but that will take a while (plus some PTO soon that is in the way).

OTOH this is a community project so if there are changes to vm-builder I'm willing to review and sponsor. But IMHO we need one (1) solution to spawn VMs and maintain that and currently uvtool is more like that.