piuparts error, apt-get sigsegv

piuparts error at
https://debusine.freexian.com/freexian/elts-staging/artifact/1350055/ or
https://debusine.freexian.com/freexian/elts-staging/artifact/1348940/

Opening as discussed with helmut on #debusine.

0m7.2s DEBUG: Starting command: ['chroot', '/tmp/tmp2f832csh', 'apt-get', '-y', '--allow-downgrades', 'install', './tmp/idle-python3.5_3.5.3-1+deb9u12_all.deb', './tmp/libpython3.5-dbg_3.5.3-1+deb9u12_amd64.deb', './tmp/libpython3.5-dev_3.5.3-1+deb9u12_amd64.deb', './tmp/libpython3.5-minimal_3.5.3-1+deb9u12_amd64.deb', './tmp/libpython3.5-stdlib_3.5.3-1+deb9u12_amd64.deb', './tmp/libpython3.5-testsuite_3.5.3-1+deb9u12_all.deb', './tmp/libpython3.5_3.5.3-1+deb9u12_amd64.deb', './tmp/python3.5-dbg_3.5.3-1+deb9u12_amd64.deb', './tmp/python3.5-dev_3.5.3-1+deb9u12_amd64.deb', './tmp/python3.5-doc_3.5.3-1+deb9u12_all.deb', './tmp/python3.5-examples_3.5.3-1+deb9u12_all.deb', './tmp/python3.5-minimal_3.5.3-1+deb9u12_amd64.deb', './tmp/python3.5-venv_3.5.3-1+deb9u12_amd64.deb', './tmp/python3.5_3.5.3-1+deb9u12_amd64.deb']
0m7.8s DUMP: 
  Reading package lists...
0m7.8s ERROR: Command failed (status=-11): ['chroot', '/tmp/tmp2f832csh', 'apt-get', '-y', '--allow-downgrades', 'install', './tmp/idle-python3.5_3.5.3-1+deb9u12_all.deb', './tmp/libpython3.5-dbg_3.5.3-1+deb9u12_amd64.deb', './tmp/libpython3.5-dev_3.5.3-1+deb9u12_amd64.deb', './tmp/libpython3.5-minimal_3.5.3-1+deb9u12_amd64.deb', './tmp/libpython3.5-stdlib_3.5.3-1+deb9u12_amd64.deb', './tmp/libpython3.5-testsuite_3.5.3-1+deb9u12_all.deb', './tmp/libpython3.5_3.5.3-1+deb9u12_amd64.deb', './tmp/python3.5-dbg_3.5.3-1+deb9u12_amd64.deb', './tmp/python3.5-dev_3.5.3-1+deb9u12_amd64.deb', './tmp/python3.5-doc_3.5.3-1+deb9u12_all.deb', './tmp/python3.5-examples_3.5.3-1+deb9u12_all.deb', './tmp/python3.5-minimal_3.5.3-1+deb9u12_amd64.deb', './tmp/python3.5-venv_3.5.3-1+deb9u12_amd64.deb', './tmp/python3.5_3.5.3-1+deb9u12_amd64.deb']
  Reading package lists...

status=-11 means apt-get got killed with SIGSEGV.

Attempting to rebuild LOCALLY (but without the exact same setup/custom scripts as debusine):

works: piuparts --keep-sources-list -b /var/cache/pbuilder/base-stretch.tgz --single-changes-list python3.5_3.5.3-1+deb9u12_amd64.changes
fails normally without sigsegv: piuparts --keep-sources-list -b ./debusine-system.tar.xz --single-changes-list python3.5_3.5.3-1+deb9u12_amd64.changes

0m36.7s DEBUG: Command ok: ['chroot', '/tmp/tmpbmh9tqqr', 'dpkg-query', '-W', '-f', '${Status}\\t${binary:Package}\\t${Package}\\t${Version}\\n']
0m36.7s DEBUG: Starting command: ['chroot', '/tmp/tmpbmh9tqqr', 'apt-get', 'remove', '--allow-remove-essential', 'blt', 'ca-certificates', 'dh-python', 'fontconfig-config', 'fonts-dejavu-core', 'libc-dev-bin', 'libc6-dev:amd64', 'libexpat1:amd64', 'libexpat1-dev:amd64', 
'libfontconfig1:amd64', 'libfreetype6:amd64', 'libjs-jquery', 'libjs-underscore', 'libmpdec2:amd64', 'libpng16-16:amd64', 'libpython3-stdlib:amd64', 'libpython3.5:amd64', 'libpython3.5-dbg:amd64', 'libpython3.5-dev:amd64', 'libpython3.5-minimal:amd64', 'libpython3.5-stdl
ib:amd64', 'libreadline7:amd64', 'libsqlite3-0:amd64', 'libtcl8.6:amd64', 'libtk8.6:amd64', 'libx11-6:amd64', 'libx11-data', 'libxau6:amd64', 'libxcb1:amd64', 'libxdmcp6:amd64', 'libxext6:amd64', 'libxft2:amd64', 'libxrender1:amd64', 'libxss1:amd64', 'linux-libc-dev:amd6
4', 'lsb-base', 'mime-support', 'net-tools', 'openssl', 'python-pip-whl', 'python3', 'python3-minimal', 'python3-tk:amd64', 'readline-common', 'tk8.6-blt2.5', 'tzdata', 'ucf', 'x11-common', 'idle-python3.5', 'libpython3.5-testsuite', 'python3.5', 'python3.5-dbg', 'python
3.5-dev', 'python3.5-doc', 'python3.5-examples', 'python3.5-minimal', 'python3.5-venv']
0m37.2s DUMP: 
  Reading package lists...
  Building dependency tree...
  Reading state information...
  The following packages will be REMOVED:
    blt ca-certificates dh-python fontconfig-config fonts-dejavu-core
    idle-python3.5 libc-dev-bin libc6-dev libexpat1 libexpat1-dev libfontconfig1
    libfreetype6 libjs-jquery libjs-underscore libmpdec2 libpng16-16
    libpython3-stdlib libpython3.5 libpython3.5-dbg libpython3.5-dev
    libpython3.5-minimal libpython3.5-stdlib libpython3.5-testsuite libreadline7
    libsqlite3-0 libtcl8.6 libtk8.6 libx11-6 libx11-data libxau6 libxcb1
    libxdmcp6 libxext6 libxft2 libxrender1 libxss1 linux-libc-dev lsb-base
    mime-support net-tools openssl python-pip-whl python3 python3-minimal
    python3-tk python3.5 python3.5-dbg python3.5-dev python3.5-doc
    python3.5-examples python3.5-minimal python3.5-venv readline-common
    tk8.6-blt2.5 tzdata ucf x11-common
  dpkg: error: failed to open package info file '/var/lib/dpkg/available' for reading: No such file or directory
  0 upgraded, 0 newly installed, 57 to remove and 0 not upgraded.
  After this operation, 272 MB disk space will be freed.
  E: Sub-process dpkg --set-selections returned an error code (2)
  E: Couldn't record the approved state changes as dpkg selection states
0m37.2s ERROR: Command failed (status=100): ['chroot', '/tmp/tmpbmh9tqqr', 'apt-get', 'remove', '--allow-remove-essential', 'blt', 'ca-certificates', 'dh-python', 'fontconfig-config', 'fonts-dejavu-core', 'libc-dev-bin', 'libc6-dev:amd64', 'libexpat1:amd64', 'libexpat1-dev:amd64', 'libfontconfig1:amd64', 'libfreetype6:amd64', 'libjs-jquery', 'libjs-underscore', 'libmpdec2:amd64', 'libpng16-16:amd64', 'libpython3-stdlib:amd64', 'libpython3.5:amd64', 'libpython3.5-dbg:amd64', 'libpython3.5-dev:amd64', 'libpython3.5-minimal:amd64', 'libpython3.5-stdlib:amd64', 'libreadline7:amd64', 'libsqlite3-0:amd64', 'libtcl8.6:amd64', 'libtk8.6:amd64', 'libx11-6:amd64', 'libx11-data', 'libxau6:amd64', 'libxcb1:amd64', 'libxdmcp6:amd64', 'libxext6:amd64', 'libxft2:amd64', 'libxrender1:amd64', 'libxss1:amd64', 'linux-libc-dev:amd64', 'lsb-base', 'mime-support', 'net-tools', 'openssl', 'python-pip-whl', 'python3', 'python3-minimal', 'python3-tk:amd64', 'readline-common', 'tk8.6-blt2.5', 'tzdata', 'ucf', 'x11-common', 'idle-python3.5', 'libpython3.5-testsuite', 'python3.5', 'python3.5-dbg', 'python3.5-dev', 'python3.5-doc', 'python3.5-examples', 'python3.5-minimal', 'python3.5-venv']
  Reading package lists...
  Building dependency tree...
  Reading state information...
  The following packages will be REMOVED:
    blt ca-certificates dh-python fontconfig-config fonts-dejavu-core
    idle-python3.5 libc-dev-bin libc6-dev libexpat1 libexpat1-dev libfontconfig1
    libfreetype6 libjs-jquery libjs-underscore libmpdec2 libpng16-16
    libpython3-stdlib libpython3.5 libpython3.5-dbg libpython3.5-dev
    libpython3.5-minimal libpython3.5-stdlib libpython3.5-testsuite libreadline7
    libsqlite3-0 libtcl8.6 libtk8.6 libx11-6 libx11-data libxau6 libxcb1
    libxdmcp6 libxext6 libxft2 libxrender1 libxss1 linux-libc-dev lsb-base
    mime-support net-tools openssl python-pip-whl python3 python3-minimal
    python3-tk python3.5 python3.5-dbg python3.5-dev python3.5-doc
    python3.5-examples python3.5-minimal python3.5-venv readline-common
    tk8.6-blt2.5 tzdata ucf x11-common
  dpkg: error: failed to open package info file '/var/lib/dpkg/available' for reading: No such file or directory
  0 upgraded, 0 newly installed, 57 to remove and 0 not upgraded.
  After this operation, 272 MB disk space will be freed.
  E: Sub-process dpkg --set-selections returned an error code (2)
  E: Couldn't record the approved state changes as dpkg selection states