Running an non-interactive upgrade as follows:
DEBIAN_FRONTEND=noninteractive UCF_FORCE_CONFFNEW=YES sudo -E apt-get -y upgrade
which included the 2.15.0 release, I got
Setting up scm-server (2.15.0) ...
Configuration file '/etc/default/scm-server'
==> 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.
*** scm-server (Y/I/N/O/D/Z) [default=N] ?
which caused my script to hang waiting for user input.
This obviously is not respecting the non-interactivity of the upgrade process.
Shouldn't the installer respect the options supplied to apt-get, and install the new version?
If it's a one-off for this release, no problems, but if it's going to be a problem with future releases, it would be an issue.