Bug#868276: apt_preferences(5): explain how one would combine e.g. origin, version and release Pins

[Colomban Wendling <cwendling@hypra.fr>]

On Wed, 01 Dec 2021 21:57:49 +0100 Jérémy Lal wrote:
> I think the comma works:
>
> Pin: version 10, release o=ACME

I can't test with recent enough versions of Apt yet (I don't have 
repositories at hand that allows me to properly test this yet), but at 
least in 1.8.2.3 (buster, yeah, I know), I can't seem to combine 
multiple keywords:

> Pin: release n=buster, l=Vendor

works, but:

> Pin: release n=buster, origin "debian.vendor.tld"

does not (and applies to all "release n=buster", no warnings attached) 
-- yet they work separately, e.g. each alone in a Pin: line.

Often enough we can use some "release" tags to get our way, but it's an 
inconvenient and sad limitation -- and as mentioned in the OP, the 
documentation is unclear on the subject matter.

- Colomban

PS: my test includes 2 packages that appear both in both Debian and a 
vendor repository, one newer in Debian's n=buster, and the other newer 
in vendor's n=buster-backports.  The idea is that I should be able to 
match all Debian n=buster, Debian n=buster-backports, Vendor's n=buster 
and Vendor n=buster-backports *separately*.