When compiling kernel the "Ubuntu way", how do I add a local version modifier?

I've been experimenting with compiling my own kernel, and I'm having difficulty adding a local version modifier when following the instructions from BuildYourOwnKernel. This is the "Ubuntu way" of compiling a kernel using fakefoot debian/rules binary-generic instead of compiling from mainline using make bindeb-pkg.

When following the instructions, I'm actually successful compiling the kernel. However, the +test1 suffix I added as a local version modifier is only added to the .deb file and not on any of the files internally. As a result, I have a conflict during installation, because the name matches the currently installed kernel.

I'm using Ubuntu 22.04 Server.

$ lsb_release -aNo LSB modules are available.Distributor ID: UbuntuDescription:    Ubuntu 22.04.4 LTSRelease:    22.04Codename:   jammy

Current kernel:

$ uname -r5.15.0-113-generic

Here are the steps I've followed:

1. Install dependencies

sudo apt build-dep linux linux-image-unsigned-$(uname -r)sudo apt install fakeroot crash kexec-tools kernel-wedge libncurses5 libncurses5-dev binutils-dev

2. Download source

apt source linux-image-unsigned-$(uname -r)

3. Change into source directory

cd linux-5.15.0

4. Modify debian.master/changelog

Per the instructions:

In order to make your kernel "newer" than the stock Ubuntu kernel fromwhich you are based, you should add a local version modifier. Addsomething like "+test1" to the end of the first version number in thedebian.master/changelog file, before building.

Therefore, I've added +test1 to the end of the first version number as follows:

$ head -n1 debian.master/changeloglinux (5.15.0-113.123+test1) jammy; urgency=medium

5. Build kernel

fakeroot debian/rules cleanfakeroot debian/rules binary-headers binary-generic

After compiling, you'll see that the +test1 suffix has been added to all .deb files:

$ tree -L 1 /home/mike/home/mike├── linux-5.15.0├── linux_5.15.0-113.123.diff.gz├── linux_5.15.0-113.123.dsc├── linux_5.15.0.orig.tar.gz├── linux-buildinfo-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb├── linux-cloud-tools-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb├── linux-headers-5.15.0-113_5.15.0-113.123+test1_all.deb├── linux-headers-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb├── linux-image-unsigned-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb├── linux-modules-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb├── linux-modules-extra-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb├── linux-modules-iwlwifi-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb└── linux-tools-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb

The problem, however, is the +test1 suffix has not been added to any files within the .deb file, and as a result, there's a conflict when installing the kernel.

$ sudo dpkg -i linux-image-unsigned-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb dpkg: regarding linux-image-unsigned-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb containing linux-image-unsigned-5.15.0-113-generic: linux-image-unsigned-5.15.0-113-generic conflicts with linux-image-5.15.0-113-generic  linux-image-5.15.0-113-generic (version 5.15.0-113.123) is present and installed.dpkg: error processing archive linux-image-unsigned-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb (--install): conflicting packages - not installing linux-image-unsigned-5.15.0-113-genericErrors were encountered while processing: linux-image-unsigned-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb

The headers, however, are installed:

$ sudo dpkg -i linux-headers-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb (Reading database ... 138403 files and directories currently installed.)Preparing to unpack linux-headers-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb ...Unpacking linux-headers-5.15.0-113-generic (5.15.0-113.123+test1) over (5.15.0-113.123+test1) ...Setting up linux-headers-5.15.0-113-generic (5.15.0-113.123+test1) .../etc/kernel/header_postinst.d/dkms: * dkms: running auto installation service for kernel 5.15.0-113-generic   ...done.

But take notice that no directory includes the local version suffix +test. It appears that it simply overwrites the existing headers.

$ tree -L 1 /usr/src/usr/src├── linux-headers-5.15.0-113-generic└── python3.10

Here is a snip of the contents of linux-headers-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb:

$ dpkg -c linux-headers-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb | head -n20drwxr-xr-x root/root         0 2024-07-07 16:31 ./drwxr-xr-x root/root         0 2024-07-07 16:27 ./lib/drwxr-xr-x root/root         0 2024-07-07 16:27 ./lib/modules/drwxr-xr-x root/root         0 2024-07-07 16:27 ./lib/modules/5.15.0-113-generic/drwxr-xr-x root/root         0 2024-07-07 16:31 ./usr/drwxr-xr-x root/root         0 2024-07-07 16:31 ./usr/share/drwxr-xr-x root/root         0 2024-07-07 16:31 ./usr/share/doc/drwxr-xr-x root/root         0 2024-07-07 16:31 ./usr/share/doc/linux-headers-5.15.0-113-generic/-rw-r--r-- root/root    714273 2024-07-07 15:58 ./usr/share/doc/linux-headers-5.15.0-113-generic/changelog.Debian.gz-rw-r--r-- root/root      1292 2024-07-07 15:58 ./usr/share/doc/linux-headers-5.15.0-113-generic/copyrightdrwxr-xr-x root/root         0 2024-07-07 16:27 ./usr/src/drwxr-xr-x root/root         0 2024-07-07 16:27 ./usr/src/linux-headers-5.15.0-113-generic/-rw-r--r-- root/root    261963 2024-07-07 16:27 ./usr/src/linux-headers-5.15.0-113-generic/.config-rw-r--r-- root/root        39 2024-07-07 16:27 ./usr/src/linux-headers-5.15.0-113-generic/.gitignore-rw-r--r-- root/root      1013 2024-07-07 16:27 ./usr/src/linux-headers-5.15.0-113-generic/.missing-syscalls.d-rw-r--r-- root/root   1818060 2024-07-07 16:27 ./usr/src/linux-headers-5.15.0-113-generic/Module.symversdrwxr-xr-x root/root         0 2024-07-07 16:27 ./usr/src/linux-headers-5.15.0-113-generic/arch/drwxr-xr-x root/root         0 2024-07-07 16:27 ./usr/src/linux-headers-5.15.0-113-generic/arch/x86/drwxr-xr-x root/root         0 2024-07-07 16:27 ./usr/src/linux-headers-5.15.0-113-generic/arch/x86/entry/drwxr-xr-x root/root         0 2024-07-07 16:27 ./usr/src/linux-headers-5.15.0-113-generic/arch/x86/entry/syscalls/

Here is the contents of linux-image-unsigned-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb:

$ dpkg -c linux-image-unsigned-5.15.0-113-generic_5.15.0-113.123+test1_amd64.debdrwxr-xr-x root/root         0 2024-07-07 16:29 ./drwxr-xr-x root/root         0 2024-07-07 16:26 ./boot/-rw------- root/root  11680480 2024-07-07 16:26 ./boot/vmlinuz-5.15.0-113-genericdrwxr-xr-x root/root         0 2024-07-07 16:29 ./usr/drwxr-xr-x root/root         0 2024-07-07 16:27 ./usr/lib/drwxr-xr-x root/root         0 2024-07-07 16:27 ./usr/lib/linux/drwxr-xr-x root/root         0 2024-07-07 16:27 ./usr/lib/linux/triggers/drwxr-xr-x root/root         0 2024-07-07 16:29 ./usr/share/drwxr-xr-x root/root         0 2024-07-07 16:29 ./usr/share/doc/drwxr-xr-x root/root         0 2024-07-07 16:29 ./usr/share/doc/linux-image-unsigned-5.15.0-113-generic/-rw-r--r-- root/root    714273 2024-07-07 15:58 ./usr/share/doc/linux-image-unsigned-5.15.0-113-generic/changelog.Debian.gz-rw-r--r-- root/root      1292 2024-07-07 15:58 ./usr/share/doc/linux-image-unsigned-5.15.0-113-generic/copyright

Here is some tail output at the end of the build process. Take note of lines that indicate building package where the package does not contain +test1 yet the .deb does.

dpkg-deb: building package 'linux-image-unsigned-5.15.0-113-generic' in '../linux-image-unsigned-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb'.dh_installchangelogs -plinux-modules-5.15.0-113-genericdh_installdocs -plinux-modules-5.15.0-113-genericdh_compress -plinux-modules-5.15.0-113-genericdh_fixperms -plinux-modules-5.15.0-113-generic -X/boot/dh_shlibdeps -plinux-modules-5.15.0-113-generic dh_installdeb -plinux-modules-5.15.0-113-genericdh_installdebconf -plinux-modules-5.15.0-113-genericflock -w 60 /home/mike/linux-5.15.0/debian/.LOCK dh_gencontrol -plinux-modules-5.15.0-113-generic -- -Vlinux:rprovides='spl-modules,  spl-dkms,  zfs-modules,  zfs-dkms,  v4l2loopback-modules,  v4l2loopback-dkms, 'dpkg-gencontrol: warning: Depends field of package linux-modules-5.15.0-113-generic: substitution variable ${shlibs:Depends} used, but is not defineddpkg-gencontrol: warning: Built-Using field of package linux-modules-5.15.0-113-generic: substitution variable ${linux:BuiltUsing} used, but is not defineddh_md5sums -plinux-modules-5.15.0-113-genericdh_builddeb -plinux-modules-5.15.0-113-genericdpkg-deb: building package 'linux-modules-5.15.0-113-generic' in '../linux-modules-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb'.if [ -f debian.master/control.d/generic.inclusion-list ] ; then \                dh_installchangelogs -plinux-modules-extra-5.15.0-113-generic; \dh_installdocs -plinux-modules-extra-5.15.0-113-generic; \dh_compress -plinux-modules-extra-5.15.0-113-generic; \dh_fixperms -plinux-modules-extra-5.15.0-113-generic -X/boot/; \dh_shlibdeps -plinux-modules-extra-5.15.0-113-generic ; \dh_installdeb -plinux-modules-extra-5.15.0-113-generic; \dh_installdebconf -plinux-modules-extra-5.15.0-113-generic; \flock -w 60 /home/mike/linux-5.15.0/debian/.LOCK dh_gencontrol -plinux-modules-extra-5.15.0-113-generic -- -Vlinux:rprovides='spl-modules,  spl-dkms,  zfs-modules,  zfs-dkms,  v4l2loopback-modules,  v4l2loopback-dkms, ' ; \dh_md5sums -plinux-modules-extra-5.15.0-113-generic; \dh_builddeb -plinux-modules-extra-5.15.0-113-generic; \fidpkg-gencontrol: warning: Depends field of package linux-modules-extra-5.15.0-113-generic: substitution variable ${shlibs:Depends} used, but is not defineddpkg-deb: building package 'linux-modules-extra-5.15.0-113-generic' in '../linux-modules-extra-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb'.dh_installchangelogs -plinux-modules-iwlwifi-5.15.0-113-genericdh_installdocs -plinux-modules-iwlwifi-5.15.0-113-genericdh_compress -plinux-modules-iwlwifi-5.15.0-113-genericdh_fixperms -plinux-modules-iwlwifi-5.15.0-113-generic -X/boot/dh_shlibdeps -plinux-modules-iwlwifi-5.15.0-113-generic dh_installdeb -plinux-modules-iwlwifi-5.15.0-113-genericdh_installdebconf -plinux-modules-iwlwifi-5.15.0-113-genericflock -w 60 /home/mike/linux-5.15.0/debian/.LOCK dh_gencontrol -plinux-modules-iwlwifi-5.15.0-113-generic -- -Vlinux:rprovides='spl-modules,  spl-dkms,  zfs-modules,  zfs-dkms,  v4l2loopback-modules,  v4l2loopback-dkms, 'dpkg-gencontrol: warning: Built-Using field of package linux-modules-iwlwifi-5.15.0-113-generic: substitution variable ${linux:BuiltUsing} used, but is not defineddh_md5sums -plinux-modules-iwlwifi-5.15.0-113-genericdh_builddeb -plinux-modules-iwlwifi-5.15.0-113-generic; dpkg-deb: building package 'linux-modules-iwlwifi-5.15.0-113-generic' in '../linux-modules-iwlwifi-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb'.dh_installchangelogs -plinux-buildinfo-5.15.0-113-genericdh_installdocs -plinux-buildinfo-5.15.0-113-genericdh_compress -plinux-buildinfo-5.15.0-113-genericdh_fixperms -plinux-buildinfo-5.15.0-113-generic -X/boot/dh_shlibdeps -plinux-buildinfo-5.15.0-113-generic dh_installdeb -plinux-buildinfo-5.15.0-113-genericdh_installdebconf -plinux-buildinfo-5.15.0-113-genericflock -w 60 /home/mike/linux-5.15.0/debian/.LOCK dh_gencontrol -plinux-buildinfo-5.15.0-113-generic -- -Vlinux:rprovides='spl-modules,  spl-dkms,  zfs-modules,  zfs-dkms,  v4l2loopback-modules,  v4l2loopback-dkms, 'dpkg-gencontrol: warning: Depends field of package linux-buildinfo-5.15.0-113-generic: substitution variable ${shlibs:Depends} used, but is not defineddpkg-gencontrol: warning: Built-Using field of package linux-buildinfo-5.15.0-113-generic: substitution variable ${linux:BuiltUsing} used, but is not defineddh_md5sums -plinux-buildinfo-5.15.0-113-genericdh_builddeb -plinux-buildinfo-5.15.0-113-genericdpkg-deb: building package 'linux-buildinfo-5.15.0-113-generic' in '../linux-buildinfo-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb'.dh_installchangelogs -plinux-headers-5.15.0-113-genericdh_installdocs -plinux-headers-5.15.0-113-genericdh_compress -plinux-headers-5.15.0-113-genericdh_fixperms -plinux-headers-5.15.0-113-generic -X/boot/dh_shlibdeps -plinux-headers-5.15.0-113-generic dh_installdeb -plinux-headers-5.15.0-113-genericdh_installdebconf -plinux-headers-5.15.0-113-genericflock -w 60 /home/mike/linux-5.15.0/debian/.LOCK dh_gencontrol -plinux-headers-5.15.0-113-generic -- -Vlinux:rprovides='spl-modules,  spl-dkms,  zfs-modules,  zfs-dkms,  v4l2loopback-modules,  v4l2loopback-dkms, 'dh_md5sums -plinux-headers-5.15.0-113-genericdh_builddeb -plinux-headers-5.15.0-113-genericdpkg-deb: building package 'linux-headers-5.15.0-113-generic' in '../linux-headers-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb'.dh_installchangelogs -plinux-tools-5.15.0-113-genericdh_installdocs -plinux-tools-5.15.0-113-genericdh_compress -plinux-tools-5.15.0-113-genericdh_fixperms -plinux-tools-5.15.0-113-generic -X/boot/dh_shlibdeps -plinux-tools-5.15.0-113-generic dh_installdeb -plinux-tools-5.15.0-113-genericdh_installdebconf -plinux-tools-5.15.0-113-genericflock -w 60 /home/mike/linux-5.15.0/debian/.LOCK dh_gencontrol -plinux-tools-5.15.0-113-generic -- -Vlinux:rprovides='spl-modules,  spl-dkms,  zfs-modules,  zfs-dkms,  v4l2loopback-modules,  v4l2loopback-dkms, 'dh_md5sums -plinux-tools-5.15.0-113-genericdh_builddeb -plinux-tools-5.15.0-113-genericdpkg-deb: building package 'linux-tools-5.15.0-113-generic' in '../linux-tools-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb'.dh_installchangelogs -plinux-cloud-tools-5.15.0-113-genericdh_installdocs -plinux-cloud-tools-5.15.0-113-genericdh_compress -plinux-cloud-tools-5.15.0-113-genericdh_fixperms -plinux-cloud-tools-5.15.0-113-generic -X/boot/dh_shlibdeps -plinux-cloud-tools-5.15.0-113-generic dh_installdeb -plinux-cloud-tools-5.15.0-113-genericdh_installdebconf -plinux-cloud-tools-5.15.0-113-genericflock -w 60 /home/mike/linux-5.15.0/debian/.LOCK dh_gencontrol -plinux-cloud-tools-5.15.0-113-generic -- -Vlinux:rprovides='spl-modules,  spl-dkms,  zfs-modules,  zfs-dkms,  v4l2loopback-modules,  v4l2loopback-dkms, 'dh_md5sums -plinux-cloud-tools-5.15.0-113-genericdh_builddeb -plinux-cloud-tools-5.15.0-113-genericdpkg-deb: building package 'linux-cloud-tools-5.15.0-113-generic' in '../linux-cloud-tools-5.15.0-113-generic_5.15.0-113.123+test1_amd64.deb'.

So what's going on?

• Is this a bug?
• Is this intentional and I don't understand the process correctly?
• Or am I doing something wrong?