diff -r 4ddebf1d754a -r 0b2174b11897 lib/pvl/hosts/zone.sh
--- a/lib/pvl/hosts/zone.sh	Tue Mar 03 12:43:26 2015 +0200
+++ b/lib/pvl/hosts/zone.sh	Tue Mar 03 12:43:49 2015 +0200
@@ -51,6 +51,10 @@
     fi
 }
 
+## Update zone $INCLUDE file
+#
+#   update_zone_include etc/zone/includes/$zone var/zone/includes/$zone
+#
 function update_zone_include {
     local out="$1"
     local src="$2"
@@ -66,45 +70,15 @@
     fi
 }
 
-
-## Update list of zone $INCLUDEs from zone file
-#
-#   update_zone_includes var/include-cache/$zone etc/zones/$zone
+## Check if the given zone needs to be updated; update serial if so
 #
-function update_zone_includes {
-    local out="$1"
-    local src="$2"
-    local includes="$ZONES_INCLUDE"
-
-    if [ "$UPDATE_INCLUDES" = 1 ]; then
-        log_force "$out: Force zone includes: $src"
-    
-    elif apply_check "$out" "$src"; then
-        log_skip "$out: Skip zone includes: $src"
-        
-        return
-
-    elif [ "$UPDATE_INCLUDES" = 0 ]; then
-        log_noop "$out: Noop zone includes: $src"
-        
-        return
-    else
-        log_apply "$out: Update zone includes: $src"
-    fi
-
-    apply_cmd "$out" $OPT/bin/pvl.dns-includes \
-            --include-path=$ZONES_INCLUDE \
-            "$src"
-}
-
-## Update the cached .serial for the given zone, if the zone has changed:
-#
-#   update_serial var/serials/$zone $serial $deps...
+#   check_zone_serial var/serials/$zone $serial $zone_deps...
 #
 # Supports UPDATE_SERIAL=
-function update_zone_serial {
+function check_zone_serial {
     local out="$1"
     local serial="$2"
+    local srcs=(${@:3})
 
     local old=$(test -e "$out" && cat "$out" || echo '')
     
@@ -112,51 +86,60 @@
     if [ "$UPDATE_SERIAL" = 1 ]; then
         log_force "$out: Force serial $old <- $serial"
 
-    elif apply_check "$out" "${@:3}"; then
-        log_skip "$out: Skip serial: $old <- $serial"
-        
-        return
-
     elif [ "$UPDATE_SERIAL" = 0 ]; then
         log_noop "$out: Noop serial: $old <- $serial"
         
-        return
+        return 0
+
+    elif apply_check "$out" ${srcs[@]:-}; then
+        return 0
 
     else
         log_apply "$out: Update serial: $old <- $serial"
     fi
 
     echo "$serial" > $out
+        
+    return 1
 }
 
 ## Generate zone file from source using pvl.dns-process:
 #
 #   update_zone var/zones/$zone etc/zones/$zone var/serials/$zone
 #
-# Sets the SOA serial, and adjusts the $INCLUDE paths
+# Updates the SOA serial, and adjusts the $INCLUDE paths
 function update_zone {
+    local update_serial=
+
+    local OPTIND
+    while getopts 's:' opt; do case $opt in
+        s)  update_serial=$OPTARG ;;
+    esac done
+    shift $(($OPTIND - 1))
+
     local out="$1"
     local src="$2"
     local serial="$3"
-    local serial_opt=
-    local msg="$out: Generate zone: $src"
+    local zone_serial=
 
-    if [ -n "$serial" -a -f "$serial" ]; then
-        serial_opt="--serial=$(cat "$serial")"
-    elif [ "$UPDATE_SERIAL" = 0 ]; then
-        warn "$out: omit noop'd serial"
+    local msg="$out: Generate zone: $src"
+    local include_cache=$(include_cache_path $src)
+    local srcs=($(include_cache $include_cache))
+    
+    if check_zone_serial "$serial" $update_serial ${srcs[@]:-}; then
+        zone_serial=$(cat $serial)
+
+        log_skip "$out: Skip zone: $src @ $zone_serial <- $update_serial"
+
     else
-        fail "$out: missing serial: $serial"
-    fi
+        zone_serial=$(cat $serial)
 
-    if apply_check "$out" "${@:2}"; then
-        log_skip "$msg"
-    else
-        log_apply "$msg"
-
+        log_apply "$out: Generate zone: $src @ $zone_serial"
+    
         apply_cmd "$out" $OPT/bin/pvl.dns-process \
-                $serial_opt \
+                --serial=$zone_serial \
                 --include-path=$ZONES_INCLUDE \
+                --include-trace=$include_cache \
                 "$src"
     fi
 }