Using QGIS 2.14.0 on a Microsoft Surface Book with Windows 10, I created a geopackage from a layer using Save As...
I can successfully add a field to the geopackage's attribute table, calculate changes to its values, and then save the changes.
However, when I try to delete that field, QGIS responds with "Provider does not support deleting fields". Sure enough, the field cannot be deleted. Please see attached image.
If I repeat the process, instead using either a shapefile or a spatialite layer, I can delete the attribute field. So the problem seems to be with the geopackage.
In summary, how do I delete a geopackage attribute table field?