only chown if needed (fixes nfs issue)
diff --git a/stack.sh b/stack.sh
index a49de1a..62d5073 100755
--- a/stack.sh
+++ b/stack.sh
@@ -271,8 +271,11 @@
 # an error.  It is also useful for following along as the install occurs.
 set -o xtrace
 
+# create the destination directory and ensure it is writable by the user
 sudo mkdir -p $DEST
-sudo chown `whoami` $DEST
+if [ ! -w $DEST ]; then
+    sudo chown `whoami` $DEST
+fi
 
 # Install Packages
 # ================