/Users/pschambacher/.rbenv/versions/2.3.1/lib/ruby/2.3.0/ostruct.rb:186:in `respond_to_missing?': undefined method `key?' for nil:NilClass (NoMethodError)
	from /Users/pschambacher/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/syck-1.0.5/lib/syck.rb:145:in `transfer'
	from /Users/pschambacher/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/syck-1.0.5/lib/syck.rb:145:in `node_import'
	from /Users/pschambacher/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/syck-1.0.5/lib/syck.rb:145:in `load'
	from /Users/pschambacher/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/syck-1.0.5/lib/syck.rb:145:in `load'
	from repro.rb:6:in `<main>'