

Not using CachyOS but Arch… but after a long break from updates you should probably start by checking if your mirror is still up-to-date (doesn’t look like it when you local stuff is newer…).
Again… not my OS but this seems to be the file you could use to manually replace the mirrorlist in your /etc/pacman.d/ directory.
Edit: Also just to be sure… -Syyu will force a refresh of all databases (doubling the u would force “upgrading” even it’s an actual downgrade from your local version). You normally don’t do it because it puts extra load on the mirror, but in case of problems it won’t hurt.
PS: For the future (and although partial upgrades are normally to be avoided)… after a long break in updating the key breaking points are mirrors, then keyfile (they can be so out of date that you can’t start the update; so do them separately first - If CachyOS keeps with its usually sane naming structure the package you should first update, just to be sure, will named cachyos-keyring, but no guarantees there…), then pacman itself…
The latter is very rare but there have been a handful of major changes in pacman’s lifetime that broke down compatibility after a long time. Arch keeps a static pacman version available for these cases, so you can still do a proper update to fix it, but don’t know where CachyOS keeps it’s equivalent.
2nd Edit for sake of completion: A quick searched seems to indicate that CachyOS does not have a separate static pacman. So if everything else fails and it’s an actual problem of pacman itself (and only then, so please don’t try that just now) https://pkgbuild.com/~morganamilo/pacman-static/x86_64/bin/pacman-static has the static standalone version of pacman. So you can download this file, make it executable and run it.




That’s a totally separate error… It can happen that the keyring itself is so out of date that it blocks the update, and with it the upgrade to a newer keyring. For this reason it’s often safer after a long time to do pacman -Syu cachyos-keyring (pretending I guesse right and that’s the name of the package) first to avoid the whole update getting blocked by signature with an out-of-date-key. Yet that should not apply here.
But Ignoring the warnings you get for now… This looks like
vulkan-mesa-implicit-layersdid not replacevulkan-mesa-device-selectbut now the 32bit library versionlib32-vulkan-mesa-deviceis supposed to be replaced bycachyos/lib32-vulkan-mesa-implicit-layers, which would in turn needvulkan-mesa-implicit-layersas a dependency.What happens when you answer ‘no’ to that first question? Alternatively, is there anything keeping you from installing
vulkan-mesa-implicit-layers(thus replacingvulkan-mesa-device-select)?