YAML defaults in Fixtures

DEFAULTS: &DEFAULTS
created_on: <%= 3.weeks.ago.to_s(:db) %>
first:
name: Smurf
*DEFAULTS
second:
name: Fraggle
*DEFAULTS

When using that exact snippet, psych throws a parsing error. If one changes
"*DEFAULTS" to "<<: *DEFAULTS", it works. Is the described syntax simply
not supported yet? It seems to have been introduced in YAML 1.2<http://www.yaml.org/spec/1.2/spec.html#id2761803>
...

What version of psych? I vaguely recall early versions of it rejecting
stuff like that (that syck had previous accepted)

Fred