Cohere with Debian guidance on 3rd party repos

[unman]

Closes QubesOS/qubes-issues#7271

[marmarek]

Generally I like this change, but I worry about upgrade: if user modified the sources.list file (for example to enable testing updates), the new version will be saved in .dpkg-new, right? In that case, old file will be used, but the key in the old location will be gone. This will break installing any further updates.

Any ideas? Keep old keyring location (too) for the time being?

[DemiMarie]

Generally I like this change, but I worry about upgrade: if user modified the sources.list file (for example to enable testing updates), the new version will be saved in .dpkg-new, right? In that case, old file will be used, but the key in the old location will be gone. This will break installing any further updates.

Any ideas? Keep old keyring location (too) for the time being?

What about doing the upgrade in two steps?