Rudder

Rudder agent 3.2.4-trusty0 (CFEngine Core 3.7.1) (prepackaged from http://www.rudder-project.org/apt-3.2/) @ Ubuntu 14.04.3 LTS

Agent calls:
/usr/bin/aptitude --assume-yes --simulate --verbose full-upgrade
Aptitude is deprecated (Number of years passed). Moreover: aptitude hangs (as well, with noninteractive terminals) when reveals broken dependencies (in numbers of cases, such dependencies are seen in aptitude only).
Unsigned packages are stucking aptitude as well (without Aptitude::Cmdline::ignore-trust-violations="true") setting.

Agent calls aptitude, aptitude requests for user interaction (in non-interactive mode, yes!), agent hangs on waiting for aptitude to be terminated (nevermore), no debug logged.
Two things are needed:

1. Eliminate aptitude (use "apt-*"?)
2. Launch external checks in new thread, claim to log in case of considerable timeout.