Advanced Pacman Operation

Beyond the cheat sheet (Pacman Cheat Sheet): the knobs admins actually turn.

/etc/pacman.conf essentials

[options]
HoldPkg     = pacman glibc        # refuse removal of critical base
IgnorePkg   = linux-lts           # pin packages from updates
IgnoreGroup =
NoUpgrade   = /etc/passwd /etc/group
UseDelta    =
ParallelDownloads = 5
Color

IgnorePkg pins versions — document WHY in a comment beside it, or future-you removes mysteries angrily.
ParallelDownloads on fast links cuts update wall-time noticeably.

Query arsenal

pactree firefox              # dependency tree (from pacman-contrib)
pactree -r pipewire          # reverse: what needs this?
pacman -Qii vim | grep -i 'modified\|install reason'
pacman -Qet                  # explicitly installed, no deps-of
pacman -Qqn                 # native-repo only listing
pacman -Spu                  # what WOULD update (dry-run URLs)

Mark something explicit vs dependency (affects orphan detection):

sudo pacman -D --asexplicit python
sudo pacman -D --asdeps "$(pacman -Qqg gnome)"  # whole group example

Transaction anatomy & safety

Every -S/-R is one atomic transaction: download → check → commit. Interrupted commits resume cleanly; interrupted downloads just retry.

Database lock stuck after crash: confirm no pacman/yay running, then remove /var/lib/pacman/db.lck.

Local repository hosting

For fleets or heavy custom packaging:

# pacman.conf
[localrepo]
Server = file:///srv/localrepo
SigLevel = Optional TrustAll      # or sign properly with repo-add --key

repo-add /srv/localrepo/localrepo.db.tar.gz /srv/localrepo/*.pkg.tar.zst

Serve over HTTP for multi-machine setups; signing properly is documented in makepkg chapter (makepkg & Writing PKGBUILDs).