I'm having a weird issue with apt were it hangs during apt update. I want to enable verbose output to see what exactly is causing this problem or at least where it occurs. The manpage for apt-get doesn't seem to contain anything related.
How can I enable verbose output for apt?
The apt tools provide a number of Debug configuration options, that you can either set persistently via a file in /etc/apt/apt.conf.d or (probably more usefully) pass as a -oDebug:: option on the command line.
The Debug::pkgAcquire group looks like the most relevant for the issues that you are describing. From man apt.conf:
Debug::pkgAcquire::Worker
Log all interactions with the sub-processes that actually perform
downloads.
So for example you can try
sudo apt -oDebug::pkgAcquire::Worker=1 update
man apt.conf and search for DEBUG to get a list of these options.