Hardcode references to the widgets.

notebook/notebookapp.py

@@ -238,6 +238,20 @@ class NotebookWebApplication(web.Application):
         handlers.extend(load_handlers('services.nbconvert.handlers'))
         handlers.extend(load_handlers('services.kernelspecs.handlers'))
         handlers.extend(load_handlers('services.security.handlers'))
+        
+        # BEGIN HARDCODED WIDGETS HACK
+        try:
+            import ipywidgets
+            handlers.append(
+                (r"/nbextensions/widgets/(.*)", FileFindHandler, {
+                    'path': ipywidgets.find_static_assets(),
+                    'no_cache_paths': ['/'], # don't cache anything in nbextensions
+                }),
+            )
+        except:
+            self.log.warn('ipywidgets package not installed.  Widgets are unavailable.')
+        # END HARDCODED WIDGETS HACK
+        
         handlers.append(
             (r"/nbextensions/(.*)", FileFindHandler, {
                 'path': settings['nbextensions_path'],

notebook/static/notebook/js/main.js

@@ -50,6 +50,12 @@ require([
     ) {
     "use strict";
 
+    // BEGIN HARDCODED WIDGETS HACK
+    // Don't include in above require call, avoiding r.js
+    // and crash on import failure.
+    require(['nbextensions/widgets/notebook/js/extension'], function(){});
+    // END HARDCODED WIDGETS HACK
+
     // compat with old IPython, remove for IPython > 3.0
     window.CodeMirror = CodeMirror;