Debian's APT 2.7 Packaging Tool Begins Rolling Out "Snapshots" Support

[phoronix]

Phoronix: Debian's APT 2.7 Packaging Tool Begins Rolling Out "Snapshots" Support

Debian's APT packaging tool that is also used by downstreams like Ubuntu has begun seeing initial support for "snapshots" introduced...

https://www.phoronix.com/news/Debian-APT-2.7-Released

[lectrode]

Related to this initial snapshots code is also adding a --update argument for ensuring the command always installs the latest versions of a given package rather than honoring any snapshot-specified behavior.

This implies that including the "--update" parameter overrides the "--snapshot" parameter. However, I believe that is not functionally what it does. From the commit:

This runs update before opening the cache and sources.list for installing/upgrading.

In other words, this simply runs "apt update", which syncs the local package database cache with remote prior to checking for or installing any updates. That doesn't appear to override the "--snapshot" parameter, and looks like it can be used with or without it.

Correct me if I'm wrong...

[Sethox]

This implies that including the "--update" parameter overrides the "--snapshot" parameter. However, I believe that is not functionally what it does.

In other words, this simply runs "apt update", which syncs the local package database cache with remote prior to checking for or installing any updates. That doesn't appear to override the "--snapshot" parameter, and looks like it can be used with or without it.
Correct me if I'm wrong...

If that is correct, then talk about redundancy.

[docontra]

This implies that including the "--update" parameter overrides the "--snapshot" parameter. However, I believe that is not functionally what it does. From the commit:

In other words, this simply runs "apt update", which syncs the local package database cache with remote prior to checking for or installing any updates. That doesn't appear to override the "--snapshot" parameter, and looks like it can be used with or without it.

Correct me if I'm wrong...

You stand rightened

If that is correct, then talk about redundancy.

After reading the fine documentation('s diff ), it makes sense when combined with --snapshot (apt needs the lists from that moment in time to work its magic). It may also make sense in the future to make "apt --update dist-upgrade", "apt --update install foo", etc. a single transaction (single apt lock for the entire run) which will make it behave more like yum/dnf for the people that like that sort of thing¹, but the code's not there yet.

Gotta admit, when I read snapshots I thought apt had gained support for generating $NEWFANGLED_FS_SNAPSHOTS and rolling back . This is cool-ish, but to me seems to have limited use (both Debian and Ubuntu structure their archives so that you nearly always have an older release of a package, typically the very first in your version's release cycle) but it does look mighty useful for the folks running testing/unstable/unstable+experimental.

¹: I'm not in that camp (esp. after finding the hard way that running the equivalent of apt search as an unprivileged user in Big Blue land by default fetches yet another copy of the package listings ). That said, a properly implemented apt --update dist-upgrade looks dope . And yes, I am aware other options exist without said flaw (pacman, which I use and love )

[Tobu]

Cool! This looks like an easy way to use snapshot.debian.org (already very useful through debbisect). I am not sure if there is an Ubuntu equivalent at the moment.

[royce]

This implies that including the "--update" parameter overrides the "--snapshot" parameter. However, I believe that is not functionally what it does. From the commit:

In other words, this simply runs "apt update", which syncs the local package database cache with remote prior to checking for or installing any updates. That doesn't appear to override the "--snapshot" parameter, and looks like it can be used with or without it.

Correct me if I'm wrong...

Two data points to syncronise when it comes to package management: list of packages installed, and versions of those packages. --update and --snapshot together will give you a snapshot of the list of packages installed, but on their latest versions available.