In some rare cases I need to debug some networking protocols and my target of interest is NTP. I am debugging an issue where (maybe) NTP sets the current time backwards about two hours. My first candidate to look deeper is ntpd.
But what do I see… debugging option is disabled in the Debian squeeze package of ntp. WTF?! – the only nice way to do useful debugging without wireshark. The good thing is that Ubuntu had the same miss-configuration and got it fixed.
So I only need to rebuild the ntpd package with debugging enabled.
sudo apt-get build-dep ntpd
sudo apt-get source ntpd
dpkg-buildpackage -rfakeroot -uc -b
The result is a deb in the parent folder.