Try following enso program:
```
main =
here.debug

foreign js debug = """
debugger;

```
it crashes the engine with exception:
```
Execution finished with an error: java.lang.ClassCastException: class com.oracle.truffle.js.runtime.builtins.JSFunctionObject$Unbound cannot be cast to class org.enso.interpreter.runtime.callable.CallerInfo (com.oracle.truffle.js.runtime.builtins.JSFunctionObject$Unbound and org.enso.interpreter.runtime.callable.CallerInfo are in unnamed module of loader com.oracle.graalvm.locator.GraalVMLocator$GuestLangToolsLoader @55cb6996)
at <java> org.enso.interpreter.runtime.callable.function.Function$ArgumentsHelper.getCallerInfo(Function.java:352)
at <java> org.enso.interpreter.instrument.ReplDebuggerInstrument$ReplExecutionEventNodeImpl.onEnter(ReplDebuggerInstrument.java:179)
at <java> org.graalvm.truffle/com.oracle.truffle.api.instrumentation.ProbeNode$EventProviderChainNode.innerOnEnter(ProbeNode.java:1397)
at <java> org.graalvm.truffle/com.oracle.truffle.api.instrumentation.ProbeNode$EventChainNode.onEnter(ProbeNode.java:912)
at <java> org.graalvm.truffle/com.oracle.truffle.api.instrumentation.ProbeNode.onEnter(ProbeNode.java:216)
at <java> com.oracle.truffle.js.nodes.JavaScriptNodeWrapper.execute(JavaScriptNodeWrapper.java:44)
at <java> com.oracle.truffle.js.nodes.control.DiscardResultNode.execute(DiscardResultNode.java:88)
at <java> com.oracle.truffle.js.nodes.function.FunctionBodyNode.execute(FunctionBodyNode.java:73)
at <java> com.oracle.truffle.js.nodes.JavaScriptNodeWrapper.execute(JavaScriptNodeWrapper.java:45)
at <java> com.oracle.truffle.js.nodes.function.FunctionRootNode.executeInRealm(FunctionRootNode.java:150)
at <java> com.oracle.truffle.js.runtime.JavaScriptRealmBoundaryRootNode.execute(JavaScriptRealmBoundaryRootNode.java:93)
at <js> <js> poly_enso_eval(Unknown)
at <epb> <epb> null(Unknown)
at <enso> Prg.debug(Prg.enso:27-28)
```