Facter 4 user query gets overwritten when Facter is called outside of setcode in a custom fact file.
The user query is held in a static options hash, which means that nested Facter calls could override the user query. Example: https://github.com/puppetlabs/puppetlabs-docker/blob/a3c32a1b7f5b244963cd407f6037e0a86d4a3fcb/spec/unit/lib/facter/docker_spec.rb#L9