C123,

I think I saw the exact same thing, but, what I remember was it was a form of "backup" of apt-get install -=- so, if upgrade blew up your installs, you could "revert back" to what you had previously

It did see the "porting" output to a file, as the form of backup, and after running a "apt-get upgrade" your system was trashed, you could point the "backup" file into "apt-get" to revert back to what things were "before" the upgrade. I think it used dpkg though, possibly why a search for this is not coming up. I had a problem with upgrade ONLY because of the reasons mentioned here. I had Xine working fine, did a upgrade, and the Xine package was upgraded, but not the DVD library that ALSO needs to be upgraded with it. Result ended up making Xine not able to play my DVDs, a WONDERFUL Guru here just had to point me to another "update" of the DVD library that worked with the Xine upgraded package - and it worked fine.

apt-get upgrade works, its a great idea, and in "most" cases, does what it has to do - it just has a lot of work to do, and has to make "judgement" calls when two packages are going to be upgraded that "conflict" with each other. If package "A" needs library "D", and package "B" needs to use library "C" - and package "A" used to use library "C" as well -=- apt-get has to determine which package is going to do what, and possibly at the cost of one of the packages not getting what it needs.

If you read the man pages on apt-get, which helped me understand why I kept having problems whenever I did a upgrade, you realize just how "powerful" apt-get really is - amazing it isn't some form of AI programming, due to its decissions it has to make...

here is an example:

Package A - operating system module - uses library E and F...
Package B - open office program - uses library F, G, and H...

doing an apt-get upgrade, apt-get realizes that "Package A" needs to be upgraded, but not "Package B" - if it does upgrade "Package A", "Package B" will be broken because they both have the same "Library F" in them. Now apt-get "may" look to see if it can find a way to upgrade "Package B", along with "Package A" and "Library F", but it will also need to find (possibly) upgraded libraries for G and H to make dependencies for "Package B" if it is upgraded.

This, being a simple two package situation, you need to add into this, the complexity of what apt-get upgrade has to deal with, possibly hundreds of these "dependancy" issues when you run the command, and all the "decissions" it has to make. It is, no wonder, it can possibly mess something up when you do a upgrade, with all the decissions it has to make on which one is more important, and which one can be "broken".

I am sorry if my "parania" has caused anyone to be "scared" of apt-get, in particular, upgrade, but, I have had to many times that the "upgrade" has made decisions that have caused "something" not to work, and it did before the upgrade. I am quite sure the upgrade did its job, it upgraded something "important" over something less important, which is what, if you read the man pages, it is SUPPOSED to do. Xine is NOT that important, especially the "dvd" library that was broken, during the upgrade. I was able to get it resolved, and I am pretty sure, that the upgrade DID upgrade something that was a LOT more important than just a Xine library, possibly something that kept my system running, so, my parania is probably not justified. I just don't like my system to just "start" having problems, when it was working fine BEFORE I did a upgrade.

Again, sorry if my "phobic" reactions have caused anyone any alarm,
Cuddles