linux-ck-ivybridge stuck on 5.12.18-1

Question

I use the CPU optimized kernel linux-ck-ivybridge on Arch Linux using the repository below, however for unknown reasons pacman has stopped upgrading the kernel since July 2021.

It is also not listed by pacman anymore. Have they stopped offering CPU optimized kernels?

~$ sudo pacman -Syyu
[sudo] password for konrad: 
:: Synchronizing package databases...
 core                                      154.6 KiB   429 KiB/s 00:00 [########################################] 100%
 extra                                    1715.0 KiB  2.50 MiB/s 00:01 [########################################] 100%
 community                                   6.5 MiB  2.78 MiB/s 00:02 [########################################] 100%
 repo-ck                                     3.8 KiB  16.6 KiB/s 00:00 [########################################] 100%
:: Starting full system upgrade...
 there is nothing to do
~$ pacman -Ss linux-ck-ivybridge
~$ pacman -Ss linux-ck          
repo-ck/linux-ck 5.16.14-1 (ck-generic)
    The Linux-ck kernel and modules with ck's hrtimer patches
repo-ck/linux-ck-generic-v2 5.16.14-1 (ck-generic-v2)
    The Linux-ck-generic-v2 kernel and modules with ck's hrtimer patches
repo-ck/linux-ck-generic-v2-headers 5.16.14-1 (ck-generic-v2)
    Headers and scripts for building modules for Linux-ck-generic-v2 kernel
repo-ck/linux-ck-generic-v3 5.16.14-1 (ck-generic-v3)
    The Linux-ck-generic-v3 kernel and modules with ck's hrtimer patches
repo-ck/linux-ck-generic-v3-headers 5.16.14-1 (ck-generic-v3)
    Headers and scripts for building modules for Linux-ck-generic-v3 kernel
repo-ck/linux-ck-generic-v4 5.16.14-1 (ck-generic-v4)
    The Linux-ck-generic-v4 kernel and modules with ck's hrtimer patches
repo-ck/linux-ck-generic-v4-headers 5.16.14-1 (ck-generic-v4)
    Headers and scripts for building modules for Linux-ck-generic-v4 kernel
repo-ck/linux-ck-headers 5.16.14-1 (ck-generic)
    Headers and scripts for building modules for Linux-ck kernel

/etc/pacman.conf

[...]
[repo-ck]
Server = https://mirror.lesviallon.fr/$repo/os/$arch
Server = http://repo-ck.com/$arch

Answer 1

These problems are probably outlined in this article from August 2021
Con Kolivas Contemplates Ending Kernel Development, Retiring MuQSS & -ck Patches:

Con didn't get around to updating MuQSS and his -ck patches for Linux 5.13 and now with Linux 5.14 recently minted, he's been self-reflecting given the "depressingly large" changes at hand. He shared today that he's thinking of ending his -ck / MuQSS effort so for now at least no updates are planned past the existing Linux 5.12 patches.

You may still find linux-ck 5.16.15-1 for Arch, last updated recently on 2022-03-17.

You may also find Unofficial user repositories/Repo-ck.