Artifact size calculation causes NPEs

2012-07-17 17:09:26,466 WARN [1-BAM::Elastic Agent on i-c85128b0::Agent:pool-3-thread-1] [ExecuteBuildTask] Failed to execute plugin with class com.atlassian.bamboo.build.artifact.BuildArtifactPostProcessor : LOADTESTER-TRUNK-JOB1-68
java.lang.NullPointerException
        at com.atlassian.bamboo.build.artifact.AbstractArtifactManager.getTotalArtifactSize(AbstractArtifactManager.java:168)
        at com.atlassian.bamboo.build.artifact.AbstractArtifactManager.validateArtifactsSize(AbstractArtifactManager.java:77)
        at com.atlassian.bamboo.build.artifact.BuildArtifactPostProcessor.call(BuildArtifactPostProcessor.java:49)
        at com.atlassian.bamboo.build.pipeline.tasks.ExecuteBuildTask.performCustomBuildProcess(ExecuteBuildTask.java:161)
        at com.atlassian.bamboo.build.pipeline.tasks.ExecuteBuildTask.call(ExecuteBuildTask.java:87)
        at com.atlassian.bamboo.v2.build.agent.DefaultBuildAgent.build(DefaultBuildAgent.java:204)
        at com.atlassian.bamboo.v2.build.agent.BuildAgentControllerImpl.waitAndPerformBuild(BuildAgentControllerImpl.java:103)
        at com.atlassian.bamboo.v2.build.agent.DefaultBuildAgent$1.run(DefaultBuildAgent.java:109)
        at com.atlassian.bamboo.build.pipeline.concurrent.NamedThreadFactory$2.run(NamedThreadFactory.java:50)
        at java.lang.Thread.run(Thread.java:662)