Last Wednesday, we temporarily suspended upgrades to Ubuntu 24.04.1 LTS due to unforeseen issues with dependencies of installed kernel headers after release upgrades. These issues were tracked in bug 2078720 and have now been resolved, and upgrades to 24.04.1 LTS have been enabled again. Read on to see if you’re affected and how you can apply a fix.
Primary issue: Unmet kernel header dependencies after upgrade to Ubuntu 24.04.1 LTS
ubuntu-release-upgrader 1:24.04.22 enabled a new algorithm to handle obsolete packages in order to significantly improve its performance.
Unfortunately, the method it uses in APT unexpectedly failed to undo removal requests and did not return an error on failure, resulting in broken packages with APT errors such as linux-headers-6.5.0-1025-gcp : Depends: linux-gcp-6.5-headers-6.5.0-1025 but it is not installable, as APT failed to undo the removal request for linux-gcp-6.5-headers-6.5.0-1025. These errors only occurred if a kernel header for the booted kernel was installed during upgrade, and were only visible post-upgrade when trying to install or upgrade packages.
This issue has been fixed in the APT 2.4.13 update in 22.04 LTS, and upgrades from interim releases have been addressed by a fallback to the previous algorithm in the ubuntu-release-upgrader 1:24.04.23 stable release update. We are adding additional checks to our automated upgrade testing to prevent similar issues in the future.
If you are affected by this issue, you can run apt install --fix-broken to remove the old kernel headers and make apt operational again.
Secondary issue: Kernel headers removed on prior upgrades
While upgrades performed with previous ubuntu-release-upgrader versions resulted in a working package management post-upgrade, we also discovered that in those cases, the kernel headers were inadvertently removed in their entirety. This has been fixed in the ubuntu-release-upgrader 1:24.04.23 release for upgrades from interim releases. As a result, if you need to boot into the old kernel, it may lack some DKMS modules, but there are no issues with the 24.04 LTS kernels or any other package updates.