AAAPackageDev is not compatible with ST3.
But here’s the JSON version of what it is trying to create.
{ "name": "Syntax Name",
"scopeName": "source.syntax_name",
"fileTypes": ""],
"patterns":
],
"uuid": "efb5dd46-8c43-4503-8d52-cbf691a8ac29"
}
I use PlistJsonConverter to convert between XML and JSON. Be sure you use the ST3 branch of that project. You can do this by adding the ST3 branch URL as a repository to package control, then installing normally, Alternatively, you can git clone the repo and checkout the ST3 branch.