runmode has been set to dev, annotations and written, but no commentsRouter.go file has been generated 
 OS win 10 Beego version master version 
runmode = "dev"router.go
func init() {
    ns := beego.NewNamespace("/admin",
        beego.NSNamespace("/contents",
            beego.NSInclude(
                &controllers.ContentController{},
            ),
        ),
    )
    beego.AddNamespace(ns)
}controllers/content.go
type ContentController struct {
    BaseController
}
// @router / [get]
func (this *ContentController) GetContents() {
    defer this.ServeJSON()
        // .....
}