Debian updating packages
This article explains a system upgrade procedure from Debian 8 Jessie Linux to Debian 9 Stretch.Apart from the up to date Linux kernel, Stretch comes with a considerable amount of new and updated software as well as a number of packages had been rendered obsolete: This new release of Debian again comes with a lot more software than its predecessor jessie; the distribution includes over 15346 new packages, for a total of over 51687 packages.* Fix cve-2013-1776: session id hijacking from another authorized tty (closes: #701839).-- Michael Gilbert Wed, 0000 --- Changes for perl (perl perl-base perl-modules) --- perl (5.10.1-17squeeze6) stable-security; urgency=low * [SECURITY] CVE-2013-1667: fix a rehashing Do S opportunity against code that uses arbitrary user input as hash keys. 'dist-upgrade' in addition to performing the function of upgrade, also intelligently handles changing dependencies with new versions of packages; apt-get has a "smart" conflict resolution system, and it will attempt to upgrade the most important packages at the expense of less important ones if necessary.The package management system binds all the software on a Debian system together.
Debian package management consists of several layers.
Most of the software in the distribution has been updated: over 29859 software packages (this is 57% of all packages in jessie).
Also, a significant number of packages (over 6739, 13% of the packages in jessie) have for various reasons been removed from the distribution.
From this reason, remove any obsolete standard repository and 3rd-party software before you attempt the upgrade.
The command which might be helpful here is: The above command will list all packages which are no longer in a standard repository list since they were removed; thus they were rendered obsolete, or the packages were installed manually.