I found a deb file purportedly "backported" to Etch...
however, on trying to install this file, numerous errors were
generated citing a dozen or so newer versions of libraries
not installed on the system. This is confusing, as
"backported", to me, has always meant dependency problems
had been worked out, and the program would run as is on Etch.

I'd still love to use this package, but this question
remains... can I install newer lib files the package asks
for ON TOP OF older versions already installed ? In other
words, would having multiple versions of gtk, or whatever,
break the system, or, does Debian work with the files it needs,
overlooking what it doesnt ?

Im going to guess this isnt considered a sound practice...
otherwise, whats the use of [backporting] other than convenience...
if all we need is to install more libraries, almost any newer
release could be run immediately, yes ? Well, hopefully
somebody who knows the problems associated with this situation
will answer !
Thanks for reading.

Can you tell us what this mystery piece of software is, and where you got it from?

Evo2.

I just realized I didn't answer any of your questions.

The problem is that something in the code will depend on a feature only available in a newer version of some library, so that newer library will need to be backported too. In turn that library may depend on another library again with features not in the version in stable. And so on and so on. Even if you are willing to backport the required libraries you can run into conflicts where the two versions of some library explicitly conflict because they need to write files to the same location.

You can often see this type of thing if you try to build a deb binary from a deb source in testing or unstable on a stable machine. If you really want to try, have a go at building a binary deb from the source deb of the package "awesome" from testing on a lenny machine.

Cheers,

Evo2.

PS. If you manage to pull off backporting awesome I'll be extremely grateful :-)

thats funny : - ) I guess I didnt really name the package...
actually, I had the same problem with four or five packages,
all in the tone mapping series... enblend / enfuse /
qt-whatever-it-is(!) / and several related programs.

At least some of these are now fully backported to Lenny,
which should have been enough clue to me, as an Etch user,
to let the matter rest... it wont be till Debian after Lenny
when these are first included in the main distribution...
i.e., there just isnt any kind of support in Etch for
these yet.

thanks for your reply / yep Id like to try backporting