Hi,
When any user installs Ubuntu, it comes with snaps. These snaps are (sometimes? always?) taken from stable/ubuntu-<version> channel.
BUT when any user (-> me) deletes an Ubuntu snap, he has no possibility to recover this snap through this channel, except if he reminds this channel.
SO, may it be possible that these Ubuntu channels can be clearly listed in snap available channels, at least in Ubuntu sessions?
I’m no expert here, but I think we have available what you’re after already.
To list what snap packages I have installed on my current system, I can use
guiverc@d7050-next:~$ snap list
Name Version Rev Tracking Publisher Notes
bare 1.0 5 latest/stable canonicalâś“ base
chromium 116.0.5845.179 2614 latest/stable canonicalâś“ -
core 16-2.60.2 15925 latest/stable canonicalâś“ core
core22 20230801 864 latest/stable canonicalâś“ base
cups 2.4.6-4 980 latest/stable openprintingâś“ -
element-desktop 1.11.36 62 latest/stable ken-vandine✪ -
firefox 117.0-2 3068 latest/stable/… mozilla✓ -
gnome-42-2204 0+git.ff35a85 126 latest/stable/… canonical✓ -
gtk-common-themes 0.1-81-g442e511 1535 latest/stable/… canonical✓ -
snapd 2.60.3 20092 latest/stable canonicalâś“ snapd
telegram-desktop 4.9.5 5002 latest/stable telegram-desktopâś“ -
wethr 1.5.2 56 latest/stable snapcrafters✪ -
where channel is listed.
In the last hour I attempted to install a Ubuntu Desktop mantic daily, if I wanted to know what snap packages were installed by default, I could look at it’s manifest for that ISO (https://cdimage.ubuntu.com/daily-live/20230908.2/mantic-desktop-amd64.manifest - though note this is a daily so this URL will be outdated very soon; but this isn’t the case for released ISOs)
At the end of the manifest the snap packages are listed, for the daily I attempted to install (alas it failed)
snap:core22 stable 864
snap:snapd stable 20092
snap:firefox stable/ubuntu-23.10 3068
snap:gnome-42-2204 stable/ubuntu-23.10 126
snap:bare stable 5
snap:gtk-common-themes stable/ubuntu-23.10 1535
snap:snap-store stable/ubuntu-23.10 1036
snap:snapd-desktop-integration stable/ubuntu-23.10 83
snap:ubuntu-desktop-installer stable/ubuntu-23.10 1229
Is this what you’re after? Or have I missed your point completely? (sorry if that’s the case).
Thanks!
That’s what I was looking for but the point is that these Ubuntu channels could be available in App Center’s channels list of a snap, allowing any user to not use the command line after having found them! 
There’s still a problem here: what is the list of /stable/ubuntu-23.10 snaps?
I realized that chromium or cups do have this channel. But obviously they are not listed in Ubuntu iso manifest.
@dloose is there a way to include all channels (so, including ubuntu-23.10) to App Center channels list in a snap’s channels menu?
AFAIK the list of branches for a given snap is not publicly exposed anywhere
So is that a secret kept by Canonical?
These channels are usually closed immediately after release and just pointing to latest/stable… they are only used for image re-spins or for (potential) emergency fixes after this…
Ok I believed there was sometime some differences in snap’s real versioning between stable and ubuntu channels.
So atm seems that only snap-store has a different version.
Sometimes there has been, like Firefox in the latest/stable/ubuntu-23.04 channel used core22 and gnome-42-2204 when the default stable Firefox still used core20. This wasn’t really documented anywhere that I saw but I noticed it while testing 23.04.
So I agree there should be a better way to know what the default snap channels should be for a release – and maybe even some command to run to reset the default snaps to the default channels?