Since you don't see the Debug menu when looking at a Qweb report output (in HTML mode), you aren't able to see which views are being applied, as you can when customizing the Odoo UI.  Is there another trick to finding out which views are being collectively applied to generate the final output of a Qweb view?  I am working on customizing our Picking List forms, and I have (or, so I thought) removed all of the tables from the default (stock.report_picking) view.  However, one of them still shows up, so there must be a secondary view being applied.  I can't track it down, however, because when I go into Settings->Reports and find the Stock Picking report, then click on "Search associated Qweb views", it only shows the default (stock.report_picking) view.  Not even my custom view shows up in the list, so it's possible that other views may be extending the default.