Using todays's nightly build of eclipse-ide I tried to debug a simple scala+junit 4 project. The debugger is started correctly and I can step, but I can't see watch or inspect the values of any variables/parameters. Instead I get

java.lang.StringIndexOutOfBoundsException: String index out of range: 0
at java.lang.String.charAt(String.java:686)
at org.eclipse.jdt.internal.debug.eval.ast.engine.BinaryBasedSourceGenerator.isAnonymousTypeName(BinaryBasedSourceGenerator.java:495)
at org.eclipse.jdt.internal.debug.eval.ast.engine.BinaryBasedSourceGenerator.buildTypeDeclaration(BinaryBasedSourceGenerator.java:173)
at org.eclipse.jdt.internal.debug.eval.ast.engine.BinaryBasedSourceGenerator.buildTypeDeclaration(BinaryBasedSourceGenerator.java:145)
at org.eclipse.jdt.internal.debug.eval.ast.engine.BinaryBasedSourceGenerator.buildSource(BinaryBasedSourceGenerator.java:74)
at org.eclipse.jdt.internal.debug.eval.ast.engine.EvaluationSourceGenerator.getInstanceSourceMapper(EvaluationSourceGenerator.java:204)
at org.eclipse.jdt.internal.debug.eval.ast.engine.EvaluationSourceGenerator.getSource(EvaluationSourceGenerator.java:216)
at org.eclipse.jdt.internal.debug.eval.ast.engine.ASTEvaluationEngine.getCompiledExpression(ASTEvaluationEngine.java:226)
at org.eclipse.jdt.internal.debug.eval.ast.engine.ASTEvaluationEngine.evaluate(ASTEvaluationEngine.java:115)
at org.eclipse.jdt.internal.debug.ui.JavaWatchExpressionDelegate$EvaluationRunnable.run(JavaWatchExpressionDelegate.java:144)
at org.eclipse.jdt.internal.debug.core.model.JDIThread$ThreadJob.run(JDIThread.java:2751)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)