silence error from zsh when datafile is created

z.sh

@@ -57,7 +57,7 @@ _z() {
 
         # maintain the data file
         local tempfile="$datafile.$RANDOM"
-        awk < <( _z_dirs ) -v path="$*" -v now="$(date +%s)" -F"|" '
+        awk < <(_z_dirs 2>/dev/null) -v path="$*" -v now="$(date +%s)" -F"|" '
             BEGIN {
                 rank[path] = 1
                 time[path] = now