After upgrading to 1.6.6 from 1.6.5 my OpenNMS did not startup; No log messages or console output.
Inspection of /etc/init.d/opennms revealed a "$DAEMON start > /dev/null".
Running "/usr/sbin/opennms start" however revealed a nice Debian_Specific output indicating why OpenNMS did not start, shown below.
=== Output Start ===
WARNING! You have files that end in .dpkg-dist in your
OPENNMS_HOME (/usr/share/opennms) directory.
The format of the original files may have changed since
you modified them before installing a new version.
Please double-check that your configuration files are
up-to-date and delete any leftover .dpkg-dist files or
OpenNMS will not start.
=== Output End ===
In our case, simple LDAP configuration in acegi was the culprit. This check for .dpkg-dist is perhaps a new feature (we like it), or perhaps in the past we have taken the package version of our changes and merged them forwards manually (which would avoid this error, however kept our version this time on inspection of the diff)
This Debian specific start-up message, IMHO, should be readable either in the logs (controller perhaps) or on the console (I suspect that options here are limited per policy) to be effective.
A non Debian/SYSV familiar person would likely be pinging the mailing lists to figure this one out.