I've just faced this bug, which made the 18.04 to 20.04 upgrade fail. It seems that, after upgrading, DKMS tries to build LTTNG modules for the 18.04 kernel (4.15), which doesn't work.
A possible workaround is to remove this package before the upgrade, and reinstall it afterwards.
I've just faced this bug, which made the 18.04 to 20.04 upgrade fail. It seems that, after upgrading, DKMS tries to build LTTNG modules for the 18.04 kernel (4.15), which doesn't work.
A possible workaround is to remove this package before the upgrade, and reinstall it afterwards.