Question about package dependencies, package versions and distro releases

[Peter Garrett]

On Mon, 15 Jan 2007 09:43:57 +0100
Severin Schoepke <severin.schoepke at gmail.com> wrote:

> Now to my questions:
> - Is this 'bad' (using packages from another distro)?

generally yes - mixing versions can break things in new and imaginative
ways. ;-) In the case of java, you just pulled in java stuff - which I
think should be OK, but make sure you run "sudo apt-get update" or
equivalent after removing the feisty lines or the system will get
confused...

> - Packages don't seem to include information to which distro (e.g. Edgy 
> or Feisty) they belong, or do they?


Not as such - the versioning can be compared against packages.ubuntu.com I
suppose.  "apt-cache policy <packagename>" will tell you about repositories
and candidates.

> - Do packages depend 'just' on other packages or do they depend on a 
> special version of other packages?

Usually a special version or versions ( e.g. >= some revision )

> - Was I lucky that the above worked or should installing packages from 
> other distro releases always work?

You were lucky :) You can look at "pinning" if you are interested in
pusuing this - for example 

http://www.debian.org/doc/manuals/apt-howto/ch-apt-get.en.html#s-default-version
http://www.debian.org/doc/manuals/apt-howto/ch-apt-get.en.html#s-pin

You can also install the apt howto with apt ;)

sudo apt-get install apt-howto   #( try "apt-cache search apt-howto" first,
if you want to pick a language )

> - Regarding the update from Edgy to Feisty: what is the difference 
> between using apt-get dist-upgrade  and changing  all occurences of 
> 'edgy' to 'feisty' in sources.list and apt-get update && apt-get upgrade?

dist-upgrade allows the packaging system to install new packages - plain
"upgrade" just grabs updates ( security, bug fixes ) Actually , using
dist-upgrade for this is more or less deprecated in Ubuntu now - see
following.

To upgrade more easily (as in, without having to hack about with 
apt and dpkg "fix it" commands when things break ... )  it's a good idea to
read

https://help.ubuntu.com/community/EdgyUpgrades

substituting accordingly for Feisty of course... using the Update Manager
is supposed to smooth the process.

Peter