gistfile1.txt

bundle agent whatever
{
vars:
    "method" string => "generic";

    redhat|centos::
        "packagenames" slist => { "whatever" };

packages:
    any::
        "${packagenames}"
            package_policy => "add",
            package_method => ${method};
}

# RESULT: Undeclared promise body "${method}()" was referenced in a promise
# USING double quotes around "${method}" gives same error
# USING () instead of {} gives same error