psych-with-location

https://github.com/ruby/psych

Psych is a YAML parser and emitter. Psych leverages libyaml[http://pyyaml.org/wiki/LibYAML] for its YAML parsing and emitting capabilities. In addition to wrapping libyaml, Psych also knows how to serialize and de-serialize most Ruby objects to and from the YAML format. This fork provides precise location information to Psych::Handler and Psych::Nodes::Node.