NoClassDefFoundError with Eclipse Plugin

I upgraded my Eclipse platform to Version: 3.4.2, Build id: M20090211-1700,
but the problem still happens.
Here are more details. I found theese errors in the Error log window of
Eclipse:

Build compiler (scalac) crashed
java.util.NoSuchElementException: None.get
at scala.None$.get(Option.scala:150)
at scala.None$.get(Option.scala:148)
at
scala.tools.eclipse.ScalaPlugin$ProjectImpl$class.nscToLampion(ScalaPlugin.scala:377)
at scala.tools.eclipse.Driver$Project.nscToLampion(Driver.scala:16)
at
scala.tools.eclipse.ScalaPlugin$ProjectImpl$class.nscToEclipse(ScalaPlugin.scala:381)
at scala.tools.eclipse.Driver$Project.nscToEclipse(Driver.scala:16)
at
scala.tools.eclipse.ScalaPlugin$ProjectImpl$class.charSet(ScalaPlugin.scala:179)
at scala.tools.eclipse.Driver$Project.charSet(Driver.scala:16)
at scala.tools.eclipse.BuildCompiler.getSourceFile(BuildCompiler.scala:53)
at scala.tools.nsc.Global.getSourceFile(Global.scala:217)
at scala.tools.nsc.Global$Run$$anonfun$compile$1.apply(Global.scala:667)
at scala.tools.nsc.Global$Run$$anonfun$compile$1.apply(Global.scala:667)
at scala.List.map(List.scala:812)
at scala.tools.nsc.Global$Run.compile(Global.scala:667)
at scala.tools.eclipse.BuildCompiler.build(BuildCompiler.scala:113)
at
scala.tools.eclipse.ScalaPlugin$ProjectImpl$class.build(ScalaPlugin.scala:406)
at scala.tools.eclipse.Driver$Project.build(Driver.scala:16)
at lampion.eclipse.Builder.build(Builder.scala:90)
at scala.tools.eclipse.Builder.build(Builder.scala:33)
at
org.eclipse.core.internal.events.BuildManager$2.run(BuildManager.java:633)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:37)
at
org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:170)
at
org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:201)
at
org.eclipse.core.internal.events.BuildManager$1.run(BuildManager.java:253)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:37)
at
org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:256)
at
org.eclipse.core.internal.events.BuildManager.basicBuildLoop(BuildManager.java:309)
at
org.eclipse.core.internal.events.BuildManager.build(BuildManager.java:341)
at
org.eclipse.core.internal.events.AutoBuildJob.doBuild(AutoBuildJob.java:140)
at org.eclipse.core.internal.events.AutoBuildJob.run(AutoBuildJob.java:238)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)

Problems occurred when invoking code from plug-in:
"org.eclipse.core.resources".
java.util.NoSuchElementException: None.get
at scala.None$.get(Option.scala:150)
at scala.None$.get(Option.scala:148)
at
scala.tools.eclipse.ScalaPlugin$ProjectImpl$class.nscToLampion(ScalaPlugin.scala:377)
at scala.tools.eclipse.Driver$Project.nscToLampion(Driver.scala:16)
at
scala.tools.eclipse.ScalaPlugin$ProjectImpl$$anonfun$build$2.apply(ScalaPlugin.scala:410)
at
scala.tools.eclipse.ScalaPlugin$ProjectImpl$$anonfun$build$2.apply(ScalaPlugin.scala:410)
at scala.Iterator$class.foreach(Iterator.scala:414)
at
scala.collection.jcl.MutableIterator$Wrapper.foreach(MutableIterator.scala:14)
at scala.Iterable$class.foreach(Iterable.scala:256)
at scala.collection.jcl.LinkedHashSet.foreach(LinkedHashSet.scala:18)
at
scala.tools.eclipse.ScalaPlugin$ProjectImpl$class.build(ScalaPlugin.scala:410)
at scala.tools.eclipse.Driver$Project.build(Driver.scala:16)

Thanks a lot.

Bye

Franco

On Mon, May 18, 2009 at 6:17 PM, Franco Lombardo wrote:
> I upgraded my Eclipse platform to Version: 3.4.2, Build id: M20090211-1700,
> but the problem still happens.
> Here are more details. I found theese errors in the Error log window of

Does refreshing your Eclipse workspace help?

Also, is this actually a Scala project, or a Java project containing a
Scala source file?

Cheers,

Miles

> Does refreshing your Eclipse workspace help?

No, it doesn't.

> Also, is this actually a Scala project, or a Java project containing a
> Scala source file?

It's a fresh new Scala project, created by the "Create new Scala Project"
wizard.
The problems arise even when I used the "Create new Scala application"
wizard.
By the way, even my old Scala projects don't work anymore!

(Oh, I didn't mention it: I'm using Windows XP SP3, if it could help).

Thanks

Bye

Franco

On Mon, May 18, 2009 at 6:47 PM, Franco Lombardo wrote:
> By the way, even my old Scala projects don't work anymore!

Ahh ... OK, then I think that most likely your Eclipse workspace
metadata is hosed. Try creating a completely fresh workspace and
create a Hello world project there. If that succeeds then move your
old project over the the new workspace and hopefully things will sort
themselves out.

Cheers,

Miles

> Ahh ... OK, then I think that most likely your Eclipse workspace
> metadata is hosed. Try creating a completely fresh workspace and
> create a Hello world project there.

Oh, now it works!

Thanks a lot!

Bye

Franco

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http://www.francolombardo.net
Scala, Java, As400.....
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