makechrootpkg: check local pkg versions before downloading for checkpkg

Avoid always trying to download and output the according message.
Add checks for packages either not being available in the repo or
all variants have up to date versions stored in the local cache.

makechrootpkg.in

@@ -387,13 +387,19 @@ if (( ret != 0 )); then
 else
 	if (( run_checkpkg )); then
 		msg "Running checkpkg"
+		remotepkgs=($(pacman -Sddp --logfile /dev/null "${pkgnames[@]}"))
+		if (( $? )); then
+			warning "Skipped checkpkg due to missing repo packages"
+			exit 0
+		fi
+		for remotepkg in ${remotepkgs[@]}; do
+			[[ $remotepkg == file://* ]] && continue
 			msg2 "Downloading current versions"
-		if pacman --noconfirm -Swdd --logfile /dev/null "${pkgnames[@]}"; then
+			pacman --noconfirm -Swdd --logfile /dev/null "${pkgnames[@]}"
+			break
+		done
 		msg2 "Checking packages"
 		sudo -u "$makepkg_user" checkpkg --rmdir --warn
-		else
-			warning "Skipped checkpkg due to missing packages"
-		fi
 	fi
 	true
 fi