Comment 6 for bug 1939106

Thank you for taking the time to report this bug and helping to make Ubuntu better.

Quoting multiple people here:

> This is a breaking change for an update that should not happen on an LTS version.

> An upgrade requiring so much manual intervention like this should never happen in an LTS release.

You're correct about this in the general case. Unfortunately Docker is an exception. We believe that most users expect newer Docker upstream releases to be available in stable Ubuntu releases, so this is what we do. Corollary: we think that if we didn't do this, most of our Docker-using users wouldn't want to use the Docker packages we shipped at all.

However it isn't practical to us to maintain feature compatibility when upstream don't choose to do that themselves. So, as an exception for Docker, we update to newer upstream releases without concern for backwards compatibility of the behaviour of Docker itself, instead relying entirely on upstream's decisions. In this case and based solely on the analysis already presented by others here, this means that we don't expect to be patching the aufs storage driver back in to our packaging ourselves.

This is documented at https://wiki.ubuntu.com/StableReleaseUpdates where you can see the exceptions that Ubuntu makes for specific packages, and at https://wiki.ubuntu.com/DockerUpdates for the Docker group of packages specifically.

You do still have the option of using the version of Docker that shipped with a release by pinning the package to the release pocket. See apt_preferences(5) for details. However, this means that you won't receive updates (security or otherwise) for the package (and sometimes its dependencies, if they end up effectively pinned as a consequence).

Following the policy as it stands, this isn't something we expect to fix, and therefore I'm marking this bug Won't Fix. Please feel free to continue to use this bug to coordinate with others affected - for example by communicating workarounds.

If you disagree with the policy and want to make a case for it to be changed, you're welcome to do that. https://discourse.ubuntu.com/ is probably the best venue for that, and if you do post there then please link to the thread from here. However, note that you're unlikely to be successful if your proposal effectively means that you're asking others to do additional work for you, unless you also provide a workable solution for where that engineering time would come from.