Update arch

src/host/arch

@@ -3,7 +3,7 @@ _get_build_deps(){
 	needed=""
 	for i in ${builddepends[@]}
 	do
-                [ -f /info/$i ] || needed="$needed $i"
+                pacman -Qs $i > /dev/null || needed="$needed $i"
         done	
 	if [ "$needed" != "" ] ; then
 	    err "Missing: $needed"