That probably isn't this regex being wrong, but the regex at https://github.com/zaphod42/puppet/blob/9059da00db24220f43f959c03a2b31cbf8cff699/lib/puppet/settings/config_file.rb#L116 which tries to parse the `{...}` out of values.

What should the correct behavior in this case be? `rrddir` is the empty string?