Comment 16 for bug 1882088

Hi, please let me recommend a different approach to get the kernel from proposed installed:

# the package 'software-properties-common' contains the 'add-apt-repository' tool and should be installed by default these days, but anyway:
$ sudo apt install software-properties-common

# enable the proposed section of the Ubuntu archive:
$ sudo add-apt-repository "deb http://ports.ubuntu.com/ubuntu-ports/ $(lsb_release -sc)-proposed restricted main universe"

# the above should trigger an archive index update automatically these days, but anyway:
$ sudo apt update

# will see several kernel related packages:
$ apt list --upgradable | grep -i ^linux-image
linux-headers-generic/focal-proposed,focal-proposed 5.4.0.44.48 s390x [upgradable from: 5.4.0.42.46]
linux-image-generic/focal-proposed,focal-proposed 5.4.0.44.48 s390x [upgradable from: 5.4.0.42.46]
linux-libc-dev/focal-proposed,focal-proposed 5.4.0-44.48 s390x [upgradable from: 5.4.0-42.46]
linux-source-5.4.0/focal-proposed,focal-proposed 5.4.0-44.48 all [upgradable from: 5.4.0-42.46]
linux-source/focal-proposed,focal-proposed 5.4.0.44.48 all [upgradable from: 5.4.0.42.46]
linux-tools-common/focal-proposed,focal-proposed 5.4.0-44.48 all [upgradable from: 5.4.0-42.46]
linux-tools-generic/focal-proposed,focal-proposed 5.4.0.44.48 s390x [upgradable from: 5.4.0.42.46]

# you can now update to the new kernel packages (aka install them) in different way:

# 1) just install the package that's there (and trust that it's the latest version):
$ sudo apt install --install-recommends linux-image-generic
...

# 2) or by explicitly specifying the version number:
$ sudo apt install --install-recommends linux-image-generic=4.15.0.114.102

# 3) or (and probably easiest) upgrading everything to the latest available level in proposed:
$ sudo apt -y -q full-upgrade
...

# you may see messages like these:

  ┌───────────────────────┤ Pending kernel upgrade ├────────────────────────┐
  │ │
  │ Newer kernel available │
  │ │
  │ The currently running kernel version is 5.4.0-42-generic which is not │
  │ the expected kernel version . │
  │ │
  │ Restarting the system to load the new kernel will not be handled │
  │ automatically, so you should consider rebooting. │
  │ │
  │ <Ok> │
  │ │
  └─────────────────────────────────────────────────────────────────────────┘

                ┌────┤ Daemons using outdated libraries ├─────┐
                │ │
                │ │
                │ Which services should be restarted? │
                │ │
                │ [ ] dbus.service │
                │ [ ] libvirtd.service │
                │ [ ] systemd-logind.service │
                │ [ ] unattended-upgrades.service │
                │ │
                │ │
                │ <Ok> <Cancel> │
                │ │
                └─────────────────────────────────────────────┘
# that just remind you about the needed restart to make the new kernel take effect:

# old active:
$ uname -a
Linux s1lp15 5.4.0-42-generic #46 SMP Thu Jul 16 12:06:43 UTC 2020 s390x s390x s390x GNU/Linux
$ sudo reboot
exit
$ ssh ubuntu@zlin42
...
# new active:
$ uname -a
Linux s1lp15 5.4.0-44-generic #48-Ubuntu SMP Tue Aug 11 06:37:25 UTC 2020 s390x s390x s390x GNU/Linux

# if the kernel source package was installed too, you can even quickly double-check if the patch from this particular LP bug is in by looking up (grep) the LP bug number::

$ dpkg -l | grep "^.. linux-source*"
ii linux-source 5.4.0.44.48 all Linux kernel source with Ubuntu patches
ii linux-source-5.4.0 5.4.0-44.48 all Linux kernel source for version 5.4.0 with Ubuntu patches

$ apt changelog linux-source-5.4.0 | grep -C2 1882088

  * [UBUNTU 20.04] smc: SMC connections hang with later-level implementations
    (LP: #1882088)
    - net/smc: tolerate future SMCD versions

You can now do the verification ...

Hope this helps!