Agent Skills: Arch Linux Knowledge Patch

Arch Linux Knowledge Patch

Claude's baseline knowledge covers Arch Linux through mid-2024, pacman 6.x. This skill provides breaking changes and major package transitions from late 2024 onwards.

Breaking Changes Quick Reference

| Date | Change | Impact | Details | |------|--------|--------|---------| | 2024-09 | pacman 7.0 — alpm user | Downloads run unprivileged; local repos need chown :alpm | pacman-7 | | 2025-04 | Redis → Valkey | redis removed from [extra]; use valkey-cli, valkey.service | server-packages | | 2025-06 | Wine WoW64 build | Multilib no longer needed; existing 32-bit prefixes must be recreated | desktop-graphics | | 2025-06 | Plasma 6.4 Wayland-only | X11 session removed by default; install plasma-x11-session first | desktop-graphics | | 2025-06 | linux-firmware split | Vendor packages; NVIDIA symlink conflict requires pacman -Rdd workaround | desktop-graphics | | 2025-08 | Zabbix unified user | Per-component users removed; all run as zabbix | server-packages | | 2025-10 | Dovecot 2.4 | Configs incompatible with 2.3; service won't start until migrated | server-packages | | 2025-12 | .NET 10.0 default | Unversioned packages jump to 10.0; install dotnet-sdk-9.0 to keep 9.0 | server-packages | | 2025-12 | NVIDIA 590 open modules | Pascal (GTX 10xx) and older dropped; use nvidia-580xx-dkms from AUR | desktop-graphics |

pacman 7.0 (2024-09)

pacman 7.0 introduced privilege-separated downloads via a dedicated alpm system user. Packages are no longer downloaded as root.

Fix local repo access after upgrading:

chown :alpm -R /path/to/local/repo
# Ensure +x on directories so alpm user can traverse

After upgrading, merge .pacnew files (/etc/pacman.conf, /etc/makepkg.conf) to pick up new defaults.

Git source checksums may change for repos using .gitattributes — one-time PKGBUILD checksum update may be needed.

See references/pacman-7.md for details.

Valkey Replacing Redis (2025-04)

Redis was dropped from [extra] due to its license change (BSD-3-Clause to RSALv2/SSPLv1). Valkey is the BSD-licensed, API-compatible drop-in replacement.

| Old | New | |-----|-----| | redis | valkey | | redis-cli | valkey-cli | | redis-server | valkey-server | | redis.service | valkey.service |

pacman -S valkey
systemctl enable --now valkey.service

The old redis package is in the AUR only. Update all scripts and configs referencing old names.

Wine WoW64 Transition (2025-06)

wine and wine-staging switched to a pure WoW64 build. The multilib repository is no longer needed for Wine.

Breaking: Existing 32-bit Wine prefixes must be recreated:

rm -rf ~/.wine
# Then reinstall your applications

Known limitation: 32-bit apps using OpenGL directly may have reduced performance under WoW64 mode.

Plasma 6.4 — Wayland-Only Default (2025-06)

Plasma 6.4 split kwin into kwin-wayland and kwin-x11. Only Wayland is installed by default. X11 users who don't act will lose their login session.

# Install BEFORE upgrading to Plasma 6.4:
pacman -S plasma-x11-session

linux-firmware Split (2025-06)

linux-firmware was split into vendor packages (linux-firmware-nvidia, linux-firmware-intel, etc.). The meta-package depends on a default set of these.

Breaking: Upgrading from 20250508 or earlier fails due to NVIDIA firmware symlink conflicts:

pacman -Rdd linux-firmware
pacman -Syu linux-firmware

Zabbix Unified User (2025-08)

Per-component users (zabbix-server, zabbix-proxy, zabbix-agent, zabbix-web-service) are removed. All components now run as a single zabbix user from zabbix-common.

Main configs and systemd units migrate automatically. Manual fix needed for custom files:

chown zabbix:zabbix /etc/zabbix/zabbix_agentd.psk
# Update sudoers: "zabbix-agent ALL=..." → "zabbix ALL=..."

After migrating, remove obsolete accounts (userdel zabbix-server, etc.).

Dovecot 2.4 — Breaking Config (2025-10)

Dovecot 2.4 configs are incompatible with 2.3. The service will not start until migrated. The replication feature was removed.

See upstream migration guide.

Legacy fallback packages in [extra]:

pacman -S dovecot23 pigeonhole23
# Also: dovecot23-fts-elastic, dovecot23-fts-xapian

.NET 10.0 Default (2025-12)

Unversioned packages (dotnet-sdk, dotnet-runtime, aspnet-runtime) jumped to .NET 10.0. pacman may fail with dependency errors during upgrade.

Keep 9.0 alongside 10.0:

pacman -Syu aspnet-runtime-9.0
pacman -Rs aspnet-runtime
# Same pattern for dotnet-sdk-9.0, dotnet-runtime-9.0

NVIDIA 590 — Open Kernel Modules (2025-12)

Package mapping:

| Old | New | |-----|-----| | nvidia | nvidia-open | | nvidia-dkms | nvidia-open-dkms | | nvidia-lts | nvidia-lts-open |

Turing (RTX 20xx / GTX 1650) and newer transition automatically on upgrade.

Breaking for Pascal (GTX 10xx) and older — the 590 driver drops support entirely. Upgrading will break your graphical environment:

pacman -R nvidia # or nvidia-dkms / nvidia-lts
yay -S nvidia-580xx-dkms

Reference Files

| File | Contents | |------|----------| | pacman-7.md | Privilege-separated downloads, alpm user, git source checksum changes | | desktop-graphics.md | Plasma 6.4 Wayland-only, linux-firmware split, NVIDIA 590 open modules, Wine WoW64 | | server-packages.md | Valkey (Redis replacement), Zabbix unified user, Dovecot 2.4 migration, .NET 10.0 |