I ran "mvn clean package -P assemble" and looked at the output. I noticed the following message:
188 Running org.apache.accumulo.fate.zookeeper.TransactionWatcherTest
189 log4j:WARN No appenders could be found for logger (org.apache.accumulo.fate.zookeeper.TransactionWatcher).
190 log4j:WARN Please initialize the log4j system properly.
191 log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.