Occassionally, copyartifact will fail to copy the proper artifacts, throw and exception, and terminate the build. Suspected cause is concurrent builds attempting to retrieve the same artifacts at the same time. Our setup performs a build, then archives the output to artifacts. Several hundred test jobs will pull down those artifacts to run builds. During a typical build-and-test run, about one third of the test builds will fail trying to retrieve the artifacts. Copying a sample failure from the log files; all failures origina in the same method: FingerprintingCopyMethod.copyOne():

ERROR: Failed to copy artifacts from TIER_1_BUILD_SMOKE with filter: source_settings.ini
09:08:54 hudson.util.IOException2: Failed to copy D:\Jenkins\.jenkins\jobs\TIER_1_BUILD_SMOKE\builds\2012-04-28_09-07-27\archive\source_settings.ini to E:\JenkinsSlave\workspace\BUILD_WINDOWS_ALL\source_settings.ini
09:08:54 at hudson.plugins.copyartifact.FingerprintingCopyMethod.copyOne(FingerprintingCopyMethod.java:91)
09:08:54 at hudson.plugins.copyartifact.FingerprintingCopyMethod.copyAll(FingerprintingCopyMethod.java:63)
09:08:54 at hudson.plugins.copyartifact.CopyArtifact.perform(CopyArtifact.java:243)
09:08:54 at hudson.plugins.copyartifact.CopyArtifact.perform(CopyArtifact.java:215)
09:08:54 at hudson.tasks.BuildStepMonitor$1.perform(BuildStepMonitor.java:19)
09:08:54 at hudson.model.AbstractBuild$AbstractRunner.perform(AbstractBuild.java:705)
09:08:54 at hudson.model.Build$RunnerImpl.build(Build.java:178)
09:08:54 at hudson.model.Build$RunnerImpl.doRun(Build.java:139)
09:08:54 at hudson.model.AbstractBuild$AbstractRunner.run(AbstractBuild.java:475)
09:08:54 at hudson.model.Run.run(Run.java:1434)
09:08:54 at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:46)
09:08:54 at hudson.model.ResourceController.execute(ResourceController.java:88)
09:08:54 at hudson.model.Executor.run(Executor.java:239)