The last couple of builds have failed with the following error error message, taken from http://hudson.zones.apache.org/hudson/job/Hadoop-trunk/754/
Total time: 177 minutes 27 seconds
[trunk] $ ant
FATAL: command execution failed.Maybe you need to configure the job to choose one of your Ant installations?
java.io.IOException: Cannot run program "ant" (in directory "/home/hudson/hudson-slave/workspace/Hadoop-trunk/trunk"): java.io.IOException: error=2, No such file or directory