Preparing to unpack .../python-crypto_2.6.1-6ubuntu0.16.04.3_amd64.deb ...
Unpacking python-crypto (2.6.1-6ubuntu0.16.04.3) over (2.6.1-6ubuntu0.16.04.2) ...
Setting up python-crypto (2.6.1-6ubuntu0.16.04.3) ...
dpkg: error processing package qpdf (--configure):
 package qpdf is not ready for configuration
 cannot configure (current status 'half-installed')