A exception occured when build by ant - java.util.zip.ZipException: Zip file empty

java version is:

G:\im_client\spark\build>java -version
java version “1.6.0_11”
Java™ SE Runtime Environment (build 1.6.0_11-b03)
BEA JRockit® (build R27.6.3-40_o-112056-1.6.0_11-20090318-2104-windows-ia32, compiled mode)

the stack is:

[pack200] Packing with Pack200
[pack200] Source File :G:\im_client\spark\target\build\plugins\idlelinux.jar
[pack200] Dest. File :G:\im_client\spark\target\build\plugins\idlelinux.jar.pack
[pack200] java.util.zip.ZipException: Zip file empty
[pack200] at java.util.zip.ZipFile.open(Native Method)
[pack200] at java.util.zip.ZipFile.(ZipFile.java:117)
[pack200] at java.util.jar.JarFile.(JarFile.java:133)
[pack200] at java.util.jar.JarFile.(JarFile.java:97)
[pack200] at com.sun.tools.apache.ant.pack200.Pack200Task.pack(Pack200Task.java:186)
[pack200] at org.apache.tools.ant.taskdefs.Pack.execute(Pack.java:102)
[pack200] at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:275)
[pack200] at org.apache.tools.ant.Task.perform(Task.java:364)
[pack200] at org.apache.tools.ant.taskdefs.Sequential.execute(Sequential.java:64)
[pack200] at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:275)
[pack200] at org.apache.tools.ant.Task.perform(Task.java:364)
[pack200] at org.apache.tools.ant.taskdefs.MacroInstance.execute(MacroInstance.java:377)
[pack200] at sun.reflect.GeneratedMethodAccessor12.invoke(Unknown Source)
[pack200] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.ja va:25)
[pack200] at java.lang.reflect.Method.invoke(Method.java:597)
[pack200] at net.sf.antcontrib.logic.For$Reflector.call(Unknown Source)
[pack200] at net.sf.antcontrib.logic.For.doSequentialIteration(Unknown Source)
[pack200] at net.sf.antcontrib.logic.For.doTheTasks(Unknown Source)
[pack200] at net.sf.antcontrib.logic.For.execute(Unknown Source)
[pack200] at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:275)
[pack200] at org.apache.tools.ant.Task.perform(Task.java:364)
[pack200] at org.apache.tools.ant.Target.execute(Target.java:341)
[pack200] at org.apache.tools.ant.Target.performTasks(Target.java:369)
[pack200] at org.apache.tools.ant.Project.executeTarget(Project.java:1214)
[pack200] at org.apache.tools.ant.Project.executeTargets(Project.java:1062)
[pack200] at org.apache.tools.ant.Main.runBuild(Main.java:673)
[pack200] at org.apache.tools.ant.Main.startAnt(Main.java:189)
[pack200] at org.apache.tools.ant.launch.Launcher.run(Launcher.java:196)
[pack200] at org.apache.tools.ant.launch.Launcher.main(Launcher.java:55)

file idlelinux.jar is real empty. Why we need this file?

Pack200 is disabled as default in the latest version of the svn.

The idlelinux.jar is only needed for an update from 2.5.8 to 2.6.0.

In the next version I will remove the empty jars.