I'm receiving the following error on a remote agent:

Archiving artifacts
ERROR: Failed to archive artifacts: build/foo.tar.gz, package/foo.spec, build/parent_build_number, build.log
java.io.IOException: java.util.concurrent.ExecutionException: java.lang.NoClassDefFoundError: org/jruby/ext/posix/POSIXHandler
at hudson.FilePath.copyRecursiveTo(FilePath.java:2016)
at jenkins.model.StandardArtifactManager.archive(StandardArtifactManager.java:57)
at hudson.tasks.ArtifactArchiver.perform(ArtifactArchiver.java:140)
at hudson.tasks.BuildStepMonitor$1.perform(BuildStepMonitor.java:20)
at hudson.model.AbstractBuild$AbstractBuildExecution.perform(AbstractBuild.java:784)
at hudson.model.AbstractBuild$AbstractBuildExecution.performAllBuildSteps(AbstractBuild.java:756)
at hudson.model.Build$BuildExecution.post2(Build.java:183)
at hudson.model.AbstractBuild$AbstractBuildExecution.post(AbstractBuild.java:705)
at hudson.model.Run.execute(Run.java:1695)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:46)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:231)
Caused by: java.util.concurrent.ExecutionException: java.lang.NoClassDefFoundError: org/jruby/ext/posix/POSIXHandler
at hudson.remoting.Channel$3.adapt(Channel.java:755)
at hudson.remoting.Channel$3.adapt(Channel.java:750)
at hudson.remoting.FutureAdapter.get(FutureAdapter.java:55)
at hudson.FilePath.copyRecursiveTo(FilePath.java:2014)
... 11 more
Caused by: java.lang.NoClassDefFoundError: org/jruby/ext/posix/POSIXHandler
at hudson.util.IOUtils.mode(IOUtils.java:125)
at hudson.util.io.TarArchiver.visit(TarArchiver.java:101)
at hudson.util.DirScanner.scanSingle(DirScanner.java:49)
at hudson.FilePath$ExplicitlySpecifiedDirScanner.scan(FilePath.java:2540)
at hudson.FilePath.writeToTar(FilePath.java:2052)
at hudson.FilePath.access$1000(FilePath.java:172)
at hudson.FilePath$41.invoke(FilePath.java:1993)
at hudson.FilePath$41.invoke(FilePath.java:1989)
at hudson.FilePath$FileCallableWrapper.call(FilePath.java:2461)
at hudson.remoting.UserRequest.perform(UserRequest.java:118)
at hudson.remoting.UserRequest.perform(UserRequest.java:48)
at hudson.remoting.Request$2.run(Request.java:328)
at hudson.remoting.InterceptingExecutorService$1.call(InterceptingExecutorService.java:72)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:679)
Caused by: java.lang.ClassNotFoundException: org.jruby.ext.posix.POSIXHandler (WebAppClassLoader=Jenkins v1.550@478e4327 did not find class file)
at hudson.remoting.RemoteClassLoader$ClassLoaderProxy.fetch2(RemoteClassLoader.java:727)
at hudson.remoting.RemoteClassLoader$ClassLoaderProxy.fetch4(RemoteClassLoader.java:777)
at hudson.remoting.RemoteClassLoader$ClassLoaderProxy.fetch3(RemoteClassLoader.java:784)
at sun.reflect.GeneratedMethodAccessor3528.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at hudson.remoting.RemoteInvocationHandler$RPCRequest.perform(RemoteInvocationHandler.java:299)
... 7 more
Build step 'Archive the artifacts' changed build result to FAILURE
Finished: FAILURE