On Mon, 2023-03-20 at 12:27 +0100, lacsaP Patatetom wrote:
> if I understand correctly, I can install my package linux-lts-perso-
> 6.1.15-2-x86_64.pkg.tar.zst, boot on it (eg. "my" kernel) and continue
> to use the binaries present on my system while they have not been
> compiled with its (new) headers and especially for the binaries that
> call the functions present in the blk-core.c file ?

I still don't know if I understand you and
https://www.google.com/search?q=translate doesn't help.

You can install

core/linux-lts          6.1.20-1
core/linux-lts-docs     6.1.20-1
core/linux-lts-headers  6.1.20-1

and also your

linux-lts-perso         6.1.15-2
linux-lts-perso-docs    6.1.15-2
linux-lts-perso-headers 6.1.15-2

neither the version, nor the pkgrel matter.
You can run one or the other kernel and you can build modules for what
ever kernel you like, see
https://wiki.archlinux.org/title/Dynamic_Kernel_Module_Support#Rebuild_modules .

You (usually) can use a binary such as /usr/bin/vim with one or the
other kernel, but you might need to build modules to use something like
virtualbox.

In your case something like systemd or xorg is irrelevant, but something
like this might depend closer on kernel versions, than vim does.

Regards,
Ralf