Pacman -Sy Behavior: Installing New Packages After Sync Without Full Upgrade

Goal

Determine if installing a new package immediately after running pacman -Sy—without a subsequent pacman -Syu—can trigger dependency mismatches or system instability.

Constraints & Uncertainty

Testing must be performed in an isolated environment to avoid affecting production credentials. The behavior is documented but not fully verified across all Arch releases, and users sometimes employ IgnorePkg to force partial upgrades.

Specific Questions

• When a new package is installed after pacman -Sy, does pacman perform a dependency check against the pre‑upgrade database, or does it assume the database is up‑to‑date?
• What is the recommended sequence of pacman commands to safely add a package without risking a broken dependency graph?
• Can IgnorePkg be used to selectively skip upgrades without causing dependency hell, and if so, under what conditions?