Comment 45 for bug 1986781

Verification done for jammy-proposed.

...

Booting jammy-live-server-amd64.iso with `break=init`
(more details in comment #37).

(initramfs) chroot /root /bin/bash
root@ubuntu-server:/# dhclient enp1s0

root@ubuntu-server:/# add-apt-repository -y -p proposed

root@ubuntu-server:/# apt install -y casper/jammy-proposed

root@ubuntu-server:/# apt policy casper
casper:
  Installed: 1.470.2
  Candidate: 1.470.2
  Version table:
 *** 1.470.2 500
        500 http://security.ubuntu.com/ubuntu jammy-proposed/main amd64 Packages
        500 http://archive.ubuntu.com/ubuntu jammy-proposed/main amd64 Packages
        100 /var/lib/dpkg/status
...
root@ubuntu-server:/# add-apt-repository -y -p proposed -r

...

root@ubuntu-server:/# sed -i '/^ExecStart=/ s,=,=/usr/bin/strace --inject read:delay_enter=60s ,' /usr/lib/systemd/system/casper-md5check.service

root@ubuntu-server:/# cat /usr/lib/systemd/system/casper-md5check.service
[Unit]
Description=casper-md5check Verify Live ISO checksums
After=multi-user.target

[Service]
Type=oneshot
ExecStart=/usr/bin/strace --inject read:delay_enter=60s /usr/lib/casper/casper-md5check /cdrom /cdrom/md5sum.txt
...

root@ubuntu-server:/# exit
exit
(initramfs) exit
...

...
[ OK ] Reached target Multi-User System.
         Starting casper-md5check Verify Live ISO checksums...
         Starting Execute cloud user/final scripts...
...
[ OK ] Finished Execute cloud user/final scripts.
[ OK ] Reached target Cloud-init target.

Ubuntu 22.04.1 LTS ubuntu-server ttyS0

connecting...
<a few seconds later>

================================================================================
  Serial [ Help ]
================================================================================

  As the installer is running on a serial console, it has started in basic
  mode, using only the ASCII character set and black and white colours.

  If you are connecting from a terminal emulator such as gnome-terminal that
  supports unicode and rich colours you can switch to "rich mode" which uses
  unicode, colours and supports many languages.

  You can also connect to the installer over the network via SSH, which will
  allow use of rich mode.

                          [ Continue in rich mode > ]
                          [ Continue in basic mode > ]
                          [ View SSH instructions ]