Snapshot immutability is enforced by SIP/AMFI (per Security Bulletin HT212689)—you cannot rm -rf .MobileBackups; only tmutil verbs bypass the com.apple.rootless seal. iCloud Drive “Optimize Mac Storage” (Family Sharing sync) purges *file content* but retains *snapshot inode references*, inflating purgeable accounting until the snapshot TTL expires or manual thinning runs. tmutil listlocalsnapshots / confirms the stale Xcode snapshot exists; sudo tmutil deletelocalsnapshots is the supported remediation. Post-deletion, run sudo xattr -rc / to clear any residual quarantine/privacy extended attributes (Safari WebKit sandbox leftovers) that prevent diskspaced from marking blocks truly free.
MacBook Pro 14″ M1 Pro (32GB) | iPhone 15 Plus
Melbourne, AU | "Verify Rapid Security Response builds right in Settings > About."
