How to make Terraform 0.13 properly update a Terraform 0.12 state

hack-selections.js

/*
 * Put this in a place where node can find it (referenced by $SCRIPT_HOME in the driver script)
 * or figure out how to do this with JQ :)
 *
 * Basically, for every key that starts with "registry.terraform.io/hashicorp/" duplicate its value to
 * that same key with "hashicorp" translated to "-" (keep the original property too)
 */
const fs = require("fs")
const output ={};
Object.entries(JSON.parse(fs.readFileSync( "/dev/stdin" ))).forEach(([key,value]) => {
	output[key] = value;
	if (key.startsWith("registry.terraform.io/hashicorp/")) {
		output[key.replace("hashicorp","-")] = value;
	}
});
console.log(JSON.stringify(output))

hack-workspace.sh

#
# Perform whatever TF init you need to do, then run this script in the folder
# where the .terraform flder is situated
#
# This first one copies all the installed "hashicorp" plugins to the "-" namespace
#
cp -r .terraform/plugins/registry.terraform.io/hashicorp .terraform/plugins/registry.terraform.io/-
#
# The hack the "selections" file
#
cat .terraform/plugins/selections.json | node $SCRIPT_HOME/hack-selections.js > .terraform/plugins/selections.json.hacked
#
# Then activate the hacked version
#
mv .terraform/plugins/selections.json.hacked .terraform/plugins/selections.json