[DISCLAIMER: I'm using Devuan testing (ascii), thus my
comments might not be apply to other versions, jessie in
particular! (Which is BTW one reason I try to keep
silent on DNG, to not disturb the jessie release process.
But since no-one has replied to this post so far ...]

On Sun, 3 Jan 2016 17:52:48 +0000 (UTC), Go Linux wrote:
> Why are you merging the debian, backports and dmo repos? Is there a way to separate them? I have rarely used backports and always downloaded what I need from dmo when I first install and then disable it. dmo can really break things if you're not careful.

I could only speculate about the reasons why, but let me
state that one-shot pulling packets from a particular
source you thereafter disable completely seems a bit odd
to me. How do you receive updates and security fixes?
(Note: I, for one, am so far fine with having the bpo
and dmo repos merged, since I have been using those for
quite some time, but mileage varies vastly, as we all
know.)

> Avidemux is in the dmo repos. The new 2.6* qt only version leaves a lot to be desired - a very long story that took several weeks to figure out - so I took a chance and installed 2.5.6 Gtk from wheezy. Thankfully it works and I have locked the version. Now is the time that I would want to disable the dmo repo and not have to worry about newer versions of dependencies mucking things up. Is there a way to do that with the merged repos? Or will I just have to be extra vigilant every time there are updates?

If I am not completely mistaken, there is no Avidemux
package in the official Debian repositories, and there
never has been. While I can well understand your stance
on the 2.5.* --> 2.6.* Avidemux changes, there is not
much one can do, except finding someone capable and
willing to maintain the old GTK version (or even do it
yourself, if that's an option).

OTOH, if you disable deb-multimedia, you get no Avidemux
at all. While that's one possible solution, it is
presumably not the one you intended.

Bottom line: Avidemux GTK is dead (unfortunately, IMHO)
and there will come a time when it will prove near to
impossible to keep its corpse upright with a few sticks
(read: library hacks and the like) while trying to keep
away the flies. I decided to let go and let it R.I.P.

However, in case you are dead set on completely disabling
the dmo repo, you could probably make do with a bit of
apt-pinning packages with the "-dmo*" version suffix.
Yes, it's an ugly non-intuitive hack, and, even assuming
it works as expected, it might not result in what you
intended.

One more note: I have no evidence, it's really nothing
more than just a gut feeling, but I expect less breakage
to occur WRT dmo packages in the foreseeable future, since
Debian returned to distributing ffmpeg instead of the
libav fork (They did, didn't they?), and I am under the
impression that a lot of the breakage was due to
mismatches between those two.

Just my 2 hundredth of your favorite currency.

Best regards
Irrwahn