I watched the DevSummit 2016 Tech Session "Web AppBuilder for ArcGIS: Development Tools and Techniques" on the new ESRI Training site. (Also available at this link.) I followed along with the video and later reviewed the process on github. This part works fine, but Tom Wayson goes on to use yo esri-widget to create a sub-widget. I found the documentation on github, but when I use the command to install it, npm install -g generator-esri-widget, I get the result pictured below.
Does anyone know what I need to do to get this to work properly?
Also, do I need to worry about the WARN deprecated messages? I saw some comments to similar questions that said no and others that said to install the update separately.
I've never used Yeoman or Grunt (or run Node.js), so any help will be greatly appreciated.