[gentoo-dev] 2024-02-26-debianutils-drops-installkernel-dep: add news item

[Andrew Nowa Ammerlaan <andrewammerlaan@gentoo.org>]

This draft news item accompanies: 
https://github.com/gentoo/gentoo/pull/35533

Random packages requiring some tool from Debian should not cause the 
kernel installation process to change.

The dropping of the debianutils dependency in ca-certificates has 
already caused some surprises due to installkernel being depcleaned. The 
origin of the problem lies here in debianutils, users unknowingly use 
and rely on installkernel but do not have it in their world file because 
it was implicitly pulled in by some package that happens to use the 
run-parts command.

And also the other way around. If I am one of the users that wants to do 
everything manually, I should not have my 'make install' unknowingly 
altered by some package that I installed which pulled debianutils into 
the depgraph.

Drop this unused runtime dependency (which is against policy to begin 
with) and its accompanying flag.
This will be accompanied with the following news item:


Title: installkernel is no longer implicitly installed
Author: Andrew Ammerlaan <andrewammerlaan@gentoo.org>
Posted: 2024-02-26
Revision: 1
News-Item-Format: 2.0
Display-If-Installed: sys-kernel/installkernel
Display-If-Installed: >=sys-apps/debianutils-5.14-r1
Display-If-Installed: app-misc/ca-certificates

/sbin/installkernel is a script called by the kernels 'make install' as well
as by the distribution kernels post install phase. If you are reading this
then chances are you use and rely on installkernel and what follows is
essential for you.

Previously sys-kernel/installkernel was implicitly installed on many systems
via a dependency in sys-apps/debianutils. This dependency was toggled
by the "installkernel" USE flag, and enabled by default.

sys-apps/debianutils was in turn pulled in by app-misc/ca-certificates,
an essential package installed on many systems. However, this
dependency was recently removed. As a result many users may find that
sys-apps/debianutils and therefore sys-kernel/installkernel are no longer
part of the dependency graph and will therefore be cleaned up by
'emerge --depclean'.

Removing sys-kernel/installkernel from your system WILL change the
way kernels are installed by 'make install'! Instead of the versioned
/boot/vmlinuz-x.y.z that you are used to, 'make install' will simply
copy bzImage (or equivalent for you arch) into /boot. This image
may not be picked up by your bootloader or its configuration tools.

To avoid surprises from such implicit dependencies from happening
again in the future, the dependency on sys-kernel/installkernel in
sys-apps/debianutils is removed. And as such sys-kernel/installkernel
is only installed on the system if it is either explicitly selected or
pulled in via the distribution kernels (e.g. gentoo-kernel(-bin)).


User Action Required (all users)
====================

Users who currently have sys-kernel/installkernel installed, must
ensure that it is explicitly selected by explicitly emerging it:

emerge --noreplace sys-kernel/installkernel

Users who find that sys-kernel/installkernel has already been
cleaned from their systems and are therefore effected by
the change in kernel installation described above should
re-install sys-kernel/installkernel and then re-install their
kernel.

emerge sys-kernel/installkernel
cd /usr/src/linux (or other location of the kernel sources)
make install

Note that this re-installation is not required for users of the
distribution kernels (e.g. gentoo-kernel(-bin)).


See also: https://wiki.gentoo.org/wiki/Installkernel