Can only add empty custom block/template with Magento 2 Module Layout Extension

shows nothing, but if I remove the Vendorname_Package:: then magento will inject the block

but it is an empty block…

I modified vendor/magento/framework/View/Element/Template.php to inject block level debug html comments into the html source of the webpage.

So I can add the block to the page but I can never get anything to show from the template…

my file layout:

app/code/Vendorname/Package/composer.json

{
 "name": "vendorname/module-package",
 "description": "N/A",
 "require": {
   "php": "~7.1.3||~7.2.0",
   "magento/framework": "102.0.*"
 },
 "type": "magento2-module",
 "license": [
     "OSL-3.0",
     "AFL-3.0"
 ],
 "autoload": {
    "psr-4": {"Vendorname\Package\": ""},
    "files": ["registration.php"]
 },
 "version": "1.0.0"
}

app/code/Vendorname/Package/etc/module.xml

< ?xml version="1.0"?>

        

app/code/Vendorname/Package/registration.php

< ?php
use MagentoFrameworkComponentComponentRegistrar;

ComponentRegistrar::register(ComponentRegistrar::MODULE,
    'Vendorname_Package', __DIR__);

app/code/Vendorname/Package/view/frontend/layout/catalog_product_view.xml

< ?xml version="1.0"?>


        
        
        
        

app/code/Vendorname/Package/view/frontend/templates/custom_stuff.phtml

CUSTOM STUFF!!!

what am I doing wrong?