During the last update using yay I got the following message:
[darius@eos-pc ~]$ LC_ALL=C yay
:: Synchronizing package databases...
endeavouros is up to date
core is up to date
extra is up to date
multilib is up to date
:: Searching AUR for updates...
:: Searching databases for updates...
-> Packages not in AUR: reiserfsprogs
there is nothing to do
I’ve noticed that reiserfs code has been removed from the kernel, but this message is a bit confusing. How do I get rid of it?
Uninstall reiserfsprogs, but be sure to check that the package is not needed.
For example:
sudo pacman -R reiserfsprogs
what about util-linux?
[darius@eos-pc ~]$ LC_ALL=C pacman -Qi reiserfsprogs
Name : reiserfsprogs
Version : 3.6.27-5
Description : Reiserfs utilities
Architecture : x86_64
URL : https://www.kernel.org/
Licenses : GPL-2.0-only
Groups : None
Provides : None
Depends On : util-linux
Optional Deps : None
Required By : None
Optional For : None
Conflicts With : None
Replaces : None
Installed Size : 601.26 KiB
Packager : Tobias Powalowski <tpowa@archlinux.org>
Build Date : Mon Jul 1 14:37:34 2024
Install Date : Wed Jan 22 20:35:50 2025
Install Reason : Explicitly installed
Install Script : No
Validated By : Signature
No problem, util-linux does not need reiserfsprogs, it is vice versa.
You will see the potential problems with command
sudo pacman -R reiserfsprogs
It fails if it cannot continue.
thanks @manuel 
Yep, this message is confusing. Wonders of pacman not tracking what repository was used when installing a package, for good and for bad. The actual meaning is sort of “FYI: this package is not in any repository and not even in AUR”. That is, you installed it manually via a custom PKGBUILD or it was removed from whatever repository it used to be in.