deleting cell with widget works but leaves JS console error

[scottdraves]

with a fresh conda env and the following package versions:

widgetsnbextension: 2.0.0-py35_0
ipywidgets:         6.0.0-py35_0
notebook:           5.0.0-py35_0

if I create a Python 3 notebook and run a cell like this:

from ipywidgets import *
IntSlider()

and then delete the cell (i use the "x" key), it works but I get the following stack trace on the JS console:

events.js:33 Exception in event handler for delete.Cell Error: Widget not attached.
    at Function.detach (widget.js:682)
    at JupyterPhosphorWidget.Widget.dispose (widget.js:70)
    at JupyterPhosphorWidget.dispose (widget.js:666)
    at IntSliderView.DOMWidgetView.remove (widget.js:837)
    at WidgetArea.clear (widgetarea.js:156)
    at window._Events.clearWidgetArea (extension.js:70)
    at window._Events.dispatch (jquery.min.js:5)
    at window._Events.y.handle (jquery.min.js:5)
    at Object.trigger (jquery.min.js:5)
    at window._Events.<anonymous> (jquery.min.js:5) 
(2) ["delete.Cell", Object, callee: (...), Symbol(Symbol.iterator): function]

i tried in an old env i had with nb v4.2.1 and ipywidgets v4 and could not reproduce.

chrome 58 on mac.

[jasongrout]

Thanks for reporting this.

[jasongrout]

I couldn't reproduce this with notebook master-ish and ipywidgets master. We did change significantly how widgets were displayed in ipywidgets master. Can you see if you can reproduce it with ipywidgets master?

[jasongrout]

Closing as fixed in master. Please reopen if you see this still as an issue in master. Thanks for reporting this!