Immediate-Configure
Defaults to on which will cause APT to install essential and important packages as fast as possible in the install/upgrade
operation. This is done to limit the effect of a failing dpkg(1) call: If this option is disabled APT does treat an important
package in the same way as an extra package: Between the unpacking of the important package A and his configuration can then be many
other unpack or configuration calls, e.g. for package B which has no relation to A, but causes the dpkg call to fail (e.g. because
maintainer script of package B generates an error) which results in a system state in which package A is unpacked but unconfigured -
each package depending on A is now no longer guaranteed to work as their dependency on A is not longer satisfied. The immediate
configuration marker is also applied to all dependencies which can generate a problem if the dependencies e.g. form a circle as a
dependency with the immediate flag is comparable with a Pre-Dependency. So in theory it is possible that APT encounters a situation
in which it is unable to perform immediate configuration, errors out and refers to this option so the user can deactivate the
immediate configuration temporarily to be able to perform an install/upgrade again. Note the use of the word "theory" here as this
problem was only encountered by now in real world a few times in non-stable distribution versions and was caused by wrong
dependencies of the package in question or by a system in an already broken state, so you should not blindly disable this option as
the mentioned scenario above is not the only problem immediate configuration can help to prevent in the first place. Before a big
operation like dist-upgrade is run with this option disabled it should be tried to explicitly install the package APT is unable to
configure immediately, but please make sure to report your problem also to your distribution and to the APT team with the buglink
below so they can work on improving or correcting the upgrade process.