Followup-For: Bug #850760 and this happens on upgrades from stretch to sid:
Setting up nixstatsagent (1.1.2-1) ... ... Preparing to unpack .../4-nixstatsagent_1.1.2-1_amd64.deb ... Unpacking nixstatsagent (1.1.2-1) over (1.1.0-1) ... Setting up libexpat1:amd64 (2.2.0-2) ... Setting up python-pkg-resources (32.3.1-1) ... Processing triggers for libc-bin (2.24-8) ... Setting up python-psutil (5.0.1-1) ... Setting up libsqlite3-0:amd64 (3.16.2-1) ... Configuration file '/etc/nixstats.ini' ==> File on system created by you or by a script. ==> File also in package provided by package maintainer. 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. *** nixstats.ini (Y/I/N/O/D/Z) [default=N] ? dpkg: error processing package nixstatsagent (--configure): end of file on stdin at conffile prompt ... Andreas