With cauldron, rebuilt packages go in the release repository replacing the
prior version in that repo. The release repo is not configured as an updates
repository since it doesn't change, post release.

With urpmi, running "drakrpm-edit-media --expert" (as root) and selecting the
updates flag for the release repos can be done to allow mgaapplet to check
the release repos for updates. It takes much longer than checking only the
updates repos though, so don't forget to remove the flag on the updates repos
post release.

I'm not sure off hand how to do the same for dnf.

CC: (none) => davidwhodgins

> With cauldron, rebuilt packages go in the release repository
> replacing the prior version in that repo.
That is, there is no maintained 'updates' repo for Cauldron.
> The release repo is not configured as an updates repository
All this seems a satisfactory explanation.

Running Cauldron here, with 'Core release' enabled but not for updates, and 'Core updates' enabled & for updates [apparently irrelevant], I have just noticed mgaapplet telling me updates are available... Oh well, Cauldron is Cauldron.

Can we close this as 'worksforme'?

CC: (none) => lewyssmith

Discover has no update flag or anything similar on his repositories. Moreover, GNOME Software uses the same DNF PackageKit Backend, and it sees and updates on Cauldron. So Discover should see them.

> GNOME Software uses the same DNF PackageKit Backend,
> and it sees and updates on Cauldron. So Discover should see them.
Fair comment.This implies that something is discovering updated packages in Cauldron/Core_Release.
I will explore this on Cauldron; when I find out how...

CC: lewyssmith => (none)

Well, here I am in an up-to-date Cauldron system, so no updates to Discover - but the application itself.
I could see no reference to repositories other than Flatpack & Firmware sources - but wait, after a long time it has popped a long Mageia repo list! Headed 'Mageia 9 Default Source'. In which are ticked:
 Mageia Cauldron-x86_64-Tainted
 Mageia Cauldron-x86_64         (presume Core)
 Mageia 9-x86_64-Nonfree        ?
 Mageia Cauldron-x86_64-Nonfree
 Mageia 9-x86_64-Tainted        ?
[I unticked the two Mageia 9s]
In fact you have to leave it running for ages before it makes any sense. Initially it showed all graphical applications with no indication of whether they were installed or not; now it is showing them correctly installed by the option to remove, or not by the option to install.
And it shows at the bottom of the LH panel, previously 'Look for updates', now 'Up to date'.

To come back to.
This business of both Cauldron & Mageia 9 repositories is confusing.

I similarly tried Gnome Software, which was much quicker to get going. It may have had similar repo quirks, I may have already similarly fiddled, cannot recall.

Both applications are showing C

CC: (none) => lewyssmith

...Cauldron + Nonfree + Tainted UPDATE repos.
It seems to me that with Cauldron one should confine the repos ticked to the 3 basic (release) ones.

Well, I think Dave, comment 1, has this right.
I ended up configuring both Plasma Discover-Updates-Settings repos to just
 Mageia Cauldron-x86_64[-Nonfree|Tainted]
and for comparison, Gnome Software similarly.

Now, despite mgaapplet showing uodates available, neither of the applications above is indicating any update; rather, "Up to date".
This is almost certainly due to the (correct) absence of Update repos, which are conceptually not relevant. I suspect that earlier confusion was due to odd repos being ticked that should not have been.

OTOH the MCC repositories *are*- ticked for the three 'Update' repos, so maybe there is something in those. 
So in Plasma Discover-Updates-Settings, I added the three Update repos. It still showed "Up to date", even after clicking the LH panel bottom Up-to-date line.
Doing the same thing in Gnome Software, I was surprised to find that the 3 Upda

If this understanding is correct, we can close this. Dave, what think you?

....
Doing the same thing in Gnome Software, I was surprised to find the 3 Update repos *already ticked*, as if this had been picked up from the common DNF backend (comment 0) from the Plasma changes. However, it still showed "Up to date".

Dave, what think you? Can we close this?

Yes. The media.cfg has an "updates_for" setting for each of the updates repos.
https://mirror.math.princeton.edu/pub/mageia/distrib/8/x86_64/media/media_info/media.cfg for example.

The media.cfg provides the default setting for whether or not a media is used
when checking for updates.

With urpmi, users can override the setting using drakrpm-edit-media --expert.
With plasma-discover-update, if there is a way to override the setting, I
don't see it. I suspect that's intentional, so isn't considered a bug.

plasma-discover should not be used to get Mageia updates, especially with
cauldron, or for qa testers who choose to override the setting for the
testing repos.

Closing as invalid.

Status: NEW => RESOLVED
Resolution: (none) => INVALID