vanishing kernel 5.4.0-56-generic

I am SO angry about this idiotic state of affairs. We were all urged to update as a matter of urgency following the discovery of several major bugs, last week.

Now the fixed kernel has been completely withdrawn and we are left with a choice of either vulnerable systems under the old kernels, or systems that are inconsistent under the new and inexplicably withdrawn super-duper-ultra-necessary new kernels.

We are now going to have to decide whether to stick with Ubuntu moving forward, as all this manual fixing of your nonsense through the night is not my idea of fun.

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please execute the following command only once, as it will automatically gather debugging information, in a terminal:

apport-collect 1907761

When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.

I have created Bug 1907814 to complain about apport refusing to report bugs about unknown updates with an unhelpful message.

I believe these remain two separate concerns:
a) Retracting security upgrades on purpose after releasing them to non-proposed channels needs a better workflow, reverting in a lower version number is probably entirely unnecessary for smooth upgrades.

b) Apport should still be improved even if this is never done on purpose again, because there are other reasons a Package might vanish (outdated mirrors I guess) which apport should be failing gracefully about.

This affects multiple GA and HWE (including -edge) stacks.

These are the notices announcing the now missing package versions as intentional releases:
https://ubuntu.com/security/notices/USN-4658-1
https://ubuntu.com/security/notices/USN-4659-1
https://ubuntu.com/security/notices/USN-4660-1
https://ubuntu.com/security/notices/USN-4657-1

These are the "-generic" package names that should include the security backports for (among others) CVE-2020-28915 but are now missing:
linux-image-5.8.0-31-generic
linux-image-5.4.0-56-generic
linux-image-4.15.0-126-generic

These links at this moment point nowhere:
https://packages.ubuntu.com/focal/linux-image-5.8.0-31-generic
https://packages.ubuntu.com/bionic/linux-image-5.4.0-56-generic
https://packages.ubuntu.com/xenial/linux-image-4.15.0-126-generic

OK I have now officially had enough of this ToyTown Distro.

You make a severe CRITICAL mistake and then try to triage it away by insisting we use a tool that simply does not work.

This bug is not even assigned to anyone yet.

That tells me everything I need to know about whether to persist with this idiocy.

Not only are you feckless cretins, you are also incapable of fixing your own mess. And the reporting procedures are hopeless.

My recommendation to management is that we find another solution as a matter of urgency.

Goodbye.

This link is what *should* have been easily discoverable for anyone wondering about the vanished version: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1907262

Ideas:
* allow updating USNs even when no new binaries are available, simply because changelogs are *not*
* add this possibility to the list of theories ubuntu-security-status (update-manager) helpfully explains when reporting unknown packages
* make "DELETED" a more prominent feature on links from USNs (obvious: https://launchpad.net/ubuntu/+source/linux/5.4.0-56.62/+publishinghistory - not obvious: https://launchpad.net/ubuntu/+source/linux/5.4.0-56.62)

[Expired for linux-meta (Ubuntu) because there has been no activity for 60 days.]