Debugging custom visual PowerBI desktop errors

So I have created a few custom visuals, and everytime it gets really anoying when you have to track down an error that only appears in powerbi desktop. 

Is there anyway to attach a javascript debugger to the powerbi desktop process? That would really make debugging a lot easier.

Right now the error I'm getting are: 

Error Message:

An error occurred while rendering the report.

Stack Trace:

Microsoft.Mashup.Host.Document.JavaScriptException: An error occurred while rendering the report.
   at :line 0

Invocation Stack Trace:

   at Microsoft.Mashup.Host.Document.ExceptionExtensions.GetCurrentInvocationStackTrace()
   at Microsoft.Mashup.Client.ClientShared.StackTraceInfo..ctor(String exceptionStackTrace, String invocationStackTrace)
   at Microsoft.Mashup.Client.ClientShared.FeedbackErrorInfo..ctor(String message, Nullable`1 errorCode, String requestId, Exception exception)
   at Microsoft.Mashup.Client.ClientShared.UnexpectedExceptionHandler.<>c__DisplayClass1.<HandleException>b__0()
   at Microsoft.Mashup.Host.Document.SynchronizationContextExtensions.<>c__DisplayClass3.<SendAndMarshalExceptions>b__0(Object null)
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
   at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments)
   at System.Delegate.DynamicInvokeImpl(Object[] args)
   at System.Windows.Forms.Control.InvokeMarshaledCallbackDo(ThreadMethodEntry tme)
   at System.Windows.Forms.Control.InvokeMarshaledCallbackHelper(Object obj)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Windows.Forms.Control.InvokeMarshaledCallback(ThreadMethodEntry tme)
   at System.Windows.Forms.Control.InvokeMarshaledCallbacks()
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
   at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
   at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
   at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Form.ShowDialog(IWin32Window owner)
   at Microsoft.Mashup.Client.ClientShared.WindowManager.ShowDialog[T](T form, IWin32Window owner)
   at Microsoft.PowerBI.Client.Program.<>c__DisplayClassc.<Main>b__0()
   at Microsoft.Mashup.Host.Document.ExceptionHandlerExtensions.HandleExceptions(IExceptionHandler exceptionHandler, Action action)
   at Microsoft.PowerBI.Client.Program.Main(String[] args)


JS Error Message
Script error.

So my custom visual gives me a script error, or maybe it is the powerbi desktop client, how would I ever know if I cant debug, or get some better error messages. Worst thing is that the error in the above case is periodic, so I can't reliably reproduce it. 

I'm running powerbi desktop 2.35.4399.601 64-bit (maj 2016) - on windows 10 enterprise. And my custom visual worked fine before the introduction of the sandbox feature (e.g. in the march powerbi desktop version). 

Any help would be much appreciated.