Scala value slf4j is not a member of package org

I'm trying get cross compiling between 2.7.7 and 2.8.0. The package is included, this works just fine in 2.7.7. Here's the code:

package bizondemand.utils {
package logging  {

import _root_.org.slf4j.LoggerFactory

/**This code copied and pasted from http://johlrogge.wordpress.com/2009/06/27/loggingtools-in-scala/
 *
 */

I k开发者_如何学编程eep getting the "value slf4j is not a member of package org" error when I compile for 2.8 What's the magic incantation to make this work?

+ update

in sbt, and voila.