Psych::Visitors::YAMLTree#dump_exception

# File tmp/rubies/ruby-3.3.0/ext/psych/lib/psych/visitors/yaml_tree.rb, line 466
def dump_exception o, msg
  tag = ['!ruby/exception', o.class.name].join ':'

  @emitter.start_mapping nil, tag, false, Nodes::Mapping::BLOCK

  if msg
    @emitter.scalar 'message', nil, nil, true, false, Nodes::Scalar::ANY
    accept msg
  end

  @emitter.scalar 'backtrace', nil, nil, true, false, Nodes::Scalar::ANY
  accept o.backtrace

  dump_ivars o

  @emitter.end_mapping
end