The vmlinuz and initrd versions listed on the ISO Boot Kernel tab do not match.

The kernel version prior to the upgrade was 4.18.0-15.
The upgrade installed kernel version 4.18.0-18.

Notice in the output below, that vmlinuz-4.18.0-15-generic file is missing in the /boot directory, although the corresponding initrd.img-4.18.0-15-generic file is present.

$ ls -1 boot/{vmlinuz,initrd}*

    boot/initrd.img-4.18.0-15-generic
    boot/initrd.img-4.18.0-18-generic
    boot/vmlinuz-4.18.0-18-generic

This missing file causes Cubic associate the wrong files together.

Note that the kernel version used in the original 18.04.1 ISO (ubuntu-18.04.1-desktop-amd64.iso) is:

    4.15.0-29

When this ISO is exacted, the the boot directory does not contain a vmlinuz or initrd file.

This means, when `ap upgrade` is executed thes three new boot files are added to the system:
    boot/initrd.img-4.18.0-15-generic
    boot/initrd.img-4.18.0-18-generic
    boot/vmlinuz-4.18.0-18-generic

However, the following vmlinux file is not added:
    boot/vmlinuz-4.18.0-15-generic

As an additional note, the following "dangling" symlinks do exist in the root directory:
    initrd.img -> boot/initrd.img-4.15.0-29-generic
    initrd.img.old -> boot/initrd.img-4.15.0-29-generic
    vmlinuz -> boot/vmlinuz-4.15.0-29-generic
    vmlinuz.old -> boot/vmlinuz-4.15.0-29-generic

Notice, these all point to non-existent boot files for kernel 4.15.0-29.

The package "linux-image-4.18.0-15-generic" contains the missing file "/boot/vmlinuz-4.18.0-15-generic".

However, if you try to install this package, apt gives a message that the package is already installed:

$ apt install linux-image-4.18.0-15-generic
    Reading package lists... Done
    Building dependency tree
    Reading state information... Done
    linux-image-4.18.0-15-generic is already the newest version (4.18.0-15.16~18.04.1).
    linux-image-4.18.0-15-generic set to manually installed.

However, passing the "--reinstall" flag to apt solves this problem:

$ apt install --reinstall linux-image-4.18.0-15-generic

You can see that all required file are installed:

$ ls -1 /boot/{vmlinuz,initrd}*
    /boot/initrd.img-4.18.0-15-generic
    /boot/initrd.img-4.18.0-18-generic
    /boot/vmlinuz-4.18.0-15-generic
    /boot/vmlinuz-4.18.0-18-generic

Cubic's ISO Boot Kernel tab now correctly the vmlinuz and initrd file versions.

Here is a work-around until this bug is fixed:

https://answers.launchpad.net/cubic/+question/680572

Added initramfs-tools as a dependency to support querying initrd for version information.

Fixed in trunk version 2019.05-204-development

Fixed in release version 2019.05-55-release

Just updated and tried to update my existing project. When I click Next out of Chroot, cubic hung forever. Quit and then ran again from Terminal to see if anything was logged and ran into the same hang. Here is the relevant output:

  Create kernel details list
  Get vmlinuz version details
    Get vmlinuz version from file name..... /home/pico/Documents/Linux Mint 19.1
                                            Cinnamon with Updates/squashfs-
                                            root/boot/vmlinuz-4.15.0-48-generic
    The vmlinuz version is................. 4.15.0-48
  Search kernel details list for matching version
    • Kernel version....................... 4.15.0-48
    • Kernel version as integers........... (4, 15, 0, 48)
    • Vmlinuz filename..................... vmlinuz-4.15.0-48-generic
    • Directory............................ /home/pico/Documents/Linux Mint 19.1
                                            Cinnamon with Updates/squashfs-
                                            root/boot
    • Matching kernel version found?....... No
  Add new kernel details
    • Index................................ 0 of 0
    • Kernel version....................... 4.15.0-48
    • Kernel version as integers........... (4, 15, 0, 48)
    • Vmlinuz filename..................... vmlinuz-4.15.0-48-generic
    • Initrd filename...................... None
    • Directory............................ /home/pico/Documents/Linux Mint 19.1
                                            Cinnamon with Updates/squashfs-
                                            root/boot
  Get initrd version details
    Get initrd version from file name...... /home/pico/Documents/Linux Mint 19.1
                                            Cinnamon with Updates/squashfs-root/
                                            boot/initrd.img-4.15.0-20-generic
    The initrd version is.................. 4.15.0-20
  Search kernel details list for matching version
    • Kernel version....................... 4.15.0-20
    • Kernel version as integers........... (4, 15, 0, 20)
    • Initrd filename...................... initrd.img-4.15.0-20-generic
    • Directory............................ /home/pico/Documents/Linux Mint 19.1
                                            Cinnamon with Updates/squashfs-
                                            root/boot
    • Matching kernel version found?....... No
  Add new kernel details
    • Index................................ 1 of 1
    • Kernel version....................... 4.15.0-20
    • Kernel version as integers........... (4, 15, 0, 20)
    • Vmlinuz filename..................... None ...

Pico,

Thanks for reporting this.

I've opened a new bug report (Bug #1829553) for this issue.

I typically don't see comments in closed bugs, so it's a good idea to create a new bug report when an issue is encountered.