If the job two tries to clone the workspace of job one, exactly in the moment job one get's archived it will fail with:
"java.io.IOException: remote file operation failed"

Job one/the one which archives the workspace to be copied
02:29:36 Started by timer
02:29:36 [EnvInject] - Loading node environment variables.
02:29:36 Building on master in workspace /data/mozmill-ci/jenkins-master/jobs/get_mozmill-tests/workspace
02:29:36 [mozmill-tests] $ hg showconfig paths.default
02:29:36 [mozmill-tests] $ hg pull --rev default
02:29:37 [mozmill-tests] $ hg update --clean --rev default
02:29:37 0 files updated, 0 files merged, 0 files removed, 0 files unresolved
02:29:37 [mozmill-tests] $ hg log --rev . --template

{node}
02:29:37 [mozmill-tests] $ hg log --rev . --template {rev}
02:29:37 [mozmill-tests] $ hg log --rev 73fbffab24c82437116576fa8e674fab5f46f358
02:29:38 [mozmill-tests] $ hg log --template "<changeset node='{node}

' author='

{author|xmlescape}

' rev='

{rev}

' date='

{date}

'><msg>

{desc|xmlescape}

</msg><added>

{file_adds|stringify|xmlescape}

</added><deleted>

{file_dels|stringify|xmlescape}

</deleted><files>

{files|stringify|xmlescape}

</files><parents>

{parents}

</parents></changeset>\n" --rev default:0 --follow --prune 73fbffab24c82437116576fa8e674fab5f46f358 --encoding UTF-8 --encodingmode replace
02:29:38 [workspace] $ ${JENKINS_HOME}/../jenkins-env/bin/hg pull -u -R ${WORKSPACE}/mozmill-tests
02:29:39 pulling from http://hg.mozilla.org/qa/mozmill-tests
02:29:39 searching for changes
02:29:39 no changes found
02:29:39 [workspace] $ ${JENKINS_HOME}/../jenkins-env/bin/hg branches -R ${WORKSPACE}/mozmill-tests
02:29:39 mozilla-beta 4269:2b3167614438
02:29:39 mozilla-aurora 4268:18126d037e8b
02:29:39 default 4267:73fbffab24c8
02:29:39 mozilla-esr31 4254:0b8e748c6fc9
02:29:39 mozilla-release 4253:363d294779e2
02:29:39 mozilla-esr24 4212:e032a302816c
02:29:39 Archiving workspace
02:29:46 Deleting old workspace snapshot from #123868.
02:29:46 Finished: SUCCESS

Job two/the one cloning the firsts ones workspace
04:02:20 Started by user anonymous
04:02:20 [EnvInject] - Loading node environment variables.
04:02:20 Building remotely on mm-win-vista-32-4 (vista windows 32bit) in workspace c:\jenkins\workspace\release-mozilla-release_functional
04:02:20
04:02:27 Deleting project workspace... done
04:02:27
04:02:27 Restoring workspace from build #123032 of project get_mozmill-tests
04:02:27 java.io.IOException: remote file operation failed: c:\jenkins\workspace\release-mozilla-release_functional at hudson.remoting.Channel@4500a0:mm-win-vista-32-4
04:02:27 at hudson.FilePath.act(FilePath.java:910)
04:02:27 at hudson.FilePath.act(FilePath.java:887)
04:02:27 at hudson.FilePath.untar(FilePath.java:473)
04:02:27 at hudson.plugins.cloneworkspace.CloneWorkspacePublisher$WorkspaceSnapshotTar.restoreTo(CloneWorkspacePublisher.java:243)
04:02:27 at hudson.plugins.cloneworkspace.CloneWorkspaceSCM$Snapshot.restoreTo(CloneWorkspaceSCM.java:383)
04:02:27 at hudson.plugins.cloneworkspace.CloneWorkspaceSCM.checkout(CloneWorkspaceSCM.java:149)
04:02:27 at hudson.model.AbstractProject.checkout(AbstractProject.java:1414)
04:02:27 at hudson.model.AbstractBuild$AbstractBuildExecution.defaultCheckout(AbstractBuild.java:671)
04:02:27 at jenkins.scm.SCMCheckoutStrategy.checkout(SCMCheckoutStrategy.java:88)
04:02:27 at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:580)
04:02:27 at hudson.model.Run.execute(Run.java:1684)
04:02:27 at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)
04:02:27 at hudson.model.ResourceController.execute(ResourceController.java:88)
04:02:27 at hudson.model.Executor.run(Executor.java:231)
04:02:27 Caused by: java.io.IOException: Failed to extract workspace.tar.gz
04:02:27 at hudson.FilePath.readFromTar(FilePath.java:2089)
04:02:27 at hudson.FilePath.access$200(FilePath.java:172)
04:02:27 at hudson.FilePath$3.invoke(FilePath.java:475)
04:02:27 at hudson.FilePath$3.invoke(FilePath.java:473)
04:02:27 at hudson.FilePath$FileCallableWrapper.call(FilePath.java:2462)
04:02:27 at hudson.remoting.UserRequest.perform(UserRequest.java:118)
04:02:27 at hudson.remoting.UserRequest.perform(UserRequest.java:48)
04:02:27 at hudson.remoting.Request$2.run(Request.java:328)
04:02:27 at hudson.remoting.InterceptingExecutorService$1.call(InterceptingExecutorService.java:72)
04:02:27 at java.util.concurrent.FutureTask.run(Unknown Source)
04:02:27 at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
04:02:27 at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
04:02:27 at hudson.remoting.Engine$1$1.run(Engine.java:63)
04:02:27 at java.lang.Thread.run(Unknown Source)
04:02:27 Caused by: java.io.EOFException: Unexpected end of ZLIB input stream
04:02:27 at com.jcraft.jzlib.InflaterInputStream.fill(InflaterInputStream.java:186)
04:02:27 at com.jcraft.jzlib.InflaterInputStream.read(InflaterInputStream.java:106)
04:02:27 at org.apache.tools.tar.TarBuffer.readBlock(TarBuffer.java:257)
04:02:27 at org.apache.tools.tar.TarBuffer.readRecord(TarBuffer.java:223)
04:02:27 at hudson.org.apache.tools.tar.TarInputStream.getNextEntry(TarInputStream.java:228)
04:02:27 at hudson.FilePath.readFromTar(FilePath.java:2067)
04:02:27 ... 13 more
04:02:27 Archiving artifacts
04:02:28 Email was triggered for: Failure - Any
04:02:28 Sending email for trigger: Failure - Any
04:02:28 #10564 is still in progress; ignoring for purposes of comparison
04:02:28 #10564 is still in progress; ignoring for purposes of comparison
04:02:28 Sending email to: mozmill-ci@mozilla.org
04:02:29 Finished: FAILURE