Not having an encryptet root "/" partition, I get this every time:
Processing triggers for initramfs-tools (0.133) ...
update-initramfs: Generating /boot/initrd.img-5.0.5-towo.1-siduction-amd64
cryptsetup: WARNING: The initramfs image may not contain cryptsetup binaries
nor crypto modules. If that's on purpose, you may want to uninstall the
'cryptsetup-initramfs' package in order to disable the cryptsetup initramfs
integration and avoid this warning.
Configuring /dev/tty1 /dev/tty2 /dev/tty3 /dev/tty4 /dev/tty5 /dev/tty6
The charmap is UTF-8
BackSpace is ^?
Thus I purged cryptsetup-initramfs and cryptsetup, which is just an empty meta package for pulling. I instead re-install the packages cryptsetup-bin and cryptsetup-run:
Removing cryptsetup (2:2.1.0-2) ...
Removing cryptsetup-initramfs (2:2.1.0-2) ...
update-initramfs: deferring update (trigger activated)
(Reading database ... 139710 files and directories currently installed.)
Preparing to unpack .../cryptsetup-run_2%3a2.1.0-2_amd64.deb ...
Unpacking cryptsetup-run (2:2.1.0-2) over (2:2.1.0-2) ...
Preparing to unpack .../cryptsetup-bin_2%3a2.1.0-2_amd64.deb ...
Unpacking cryptsetup-bin (2:2.1.0-2) over (2:2.1.0-2) ...
Setting up cryptsetup-bin (2:2.1.0-2) ...
Setting up cryptsetup-run (2:2.1.0-2) ...
which gives this better experience when updating the kernel:
Preparing to unpack .../linux-image-5.0.5-towo.1-siduction-amd64_5.0-8_amd64.deb ...
Unpacking linux-image-5.0.5-towo.1-siduction-amd64 (5.0-8) over (5.0-8) ...
Setting up linux-image-5.0.5-towo.1-siduction-amd64 (5.0-8) ...
/etc/kernel/postinst.d/initramfs-tools:
update-initramfs: Generating /boot/initrd.img-5.0.5-towo.1-siduction-amd64
... any cryptsetup and charmap messages are gone.
You still can have an encrypted home partition but
ignore this message when having an encrypted root