Compatibility between packages of different distros and releases

[the dsc]

I would like to understand that a bit better.

Right now I'm using (k)ubuntu dapper, and I want to install a software (skype), but the most closely-related packages available are for ubuntu feisty and debian etch (which I guess that was the original basis for ubuntu, but I don't really know if it is of any relevance for the issue of installing packages).

In another forum someone said something meaning that we could install "pure" debian packages in a debian-based distribution with no problem - if I got it right. I think that "pure" debian should mean "just" debian, rather than something like kurumin, ubuntu, or knoppix... (I personally find somewhat odd that the incompatibility would be so unilateral.)

And at the same topic where I've read that, there is a link to yet another discussion where I've read that is somewhat risky to install packages from different releases... (which... intuitively at least, seems to me less risky than installing a package from a whole different distribution, even if it is the "parent" distribution... )

If I would methodically take a chance, I would install the debian etch's package, by the sum of all the things I've read up to now... my reasoning is that even though the ubuntu feisty would be more closely related than the debian, the fact that it's the next, more advanced version may also make it dependant on some thing dapper hasn't... and assuming that dapper didn't lost much of its shared characters with its ancestor, neither changed in something fundamental... the package from debian etch would work....

But if I were using Feisty, and there was a debian etch and a ubuntu dapper to pick, I'd chose the dapper...

...

Thanks in advance for any help...

[Vergil83]

As you have found, it is complicated!

Actually Dapper is kinda of based on etch (an older version of etch). The other forum is correct that you can normally install pure Debian packages. A lot of the packages in Ubuntu are directly from Debian with no changes whatsoever. A lot of the time you can do it the otherway too (Ubuntu in Debian for example). It just depends on the package. The reason a Ubuntu package might fail in Debian is Ubuntu is more cutting edge and Debian may not have something that is needed.

The "risky" part for installing something from another distro is that you are not going to get any bug fixes that everything else will automatically get. However, since Skype is closed source and is not distributed by either Ubuntu or Debian, it won't matter since the bug fixes will only come from Skype.

You are also correct that the problem with feisty is it may depend on something that you don't have installed. Something from Etch will have a better chance of being installable.

In this case, my bet is that either one will work and there is no reason one is "better" than the other.

[the dsc]

A lot of the packages in Ubuntu are directly from Debian with no changes whatsoever.

Actually, I've found that despite of separate links for debian, ubuntu, mepis and some other, all link to the same .deb package... frustrating since the installation didn't work and I was going to try to install the "other".

I think (from the kpackage's output) I'll either have to replace some package dependencies to older versions, or have both at the same time, if that's possible...

Apparently there's one that's a tar.gz, but it's under a link of "dynamic static", in the RPM-family column... but I don't know if it would make any difference, not being an actual "package", with the issue of the dependencies on outdated packages...