Installing selected packages from testing

Netrunner Netrunner Desktop 17.10
1

Hi, I am running Netrunner 17.10.
I would like to enable debian testing but keep it at low priority unless specified, so I pinned it like this:

Package: *
Pin: origin "deb.debian.org"
Pin-Priority: 10

In normal apt operations it’s being ignored, so far so good.

Now I’d like to install selected packages from it, something like this:

sudo apt install -t testing some-package

The problem is that both testing and the snapshot repository have a “testing” release, and as far as I know ‘-t’ won’t take an origin, only a release.

Are you aware of a way to do this?
Thank you in advance.

2

You can define the version of the package you want to install aswell. So apt install -t testing foo=1.0.bar. Otherwise I am not sure it makes much sense to have both activated testing and a testing snapshot. Maybe deactivating testing snapshot might be useful aswell.

3

I wanted to keep the snapshot repository to install new packages from it, otherwise they would come from testing.
I used to do that in pure debian, where I would stay on testing and install selected packages from unstable, but that was easy with the different release names.
I’m a bit surprised you can pin by origin (host name) but not do the same when you install.

4

The only workaround I see now is that testing/ is a symlink to the release name, currently buster/.
I can just call the snapshot release “buster” in sources.list and be done with it.

5

Yeah that sounds like an elegant solution if it works.

6

Well it doesn’t, not quite.
These two lines yield the same result:

apt install -t testing speedtest-cli
apt install -t buster speedtest-cli

They both use the testing repo I pinned down.

I tried going back to having “testing” in both repo declarations and updating.
Again both apt commands work.
Note that even using other releases that are present on the repo works (i.e. “stable”) but some don’t: using “sid” returns this

E: The value 'sid' is invalid for APT::Default-Release as such a release is not available in the sources

Now I really have no idea how apt is matching these release names.