Undefined method `to_sym' for #<YAML::Syck::MergeKey

I have a stock gentoo ruby/rails install. I get something like this
when I
try to use script/generate, rake migrate or script/console and probably
others.

0 wicked www/sharkwatch % ./script/console
Loading development environment.

/usr/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active_support/core_ext/hash/keys.rb:27:in
symbolize_keys':NoMethodError: undefined methodto_sym’ for
#YAML::Syck::MergeKey:0xb71dfa6c

to_sym is indeed not defined in /usr/lib/ruby/1.8/yaml.rb or
/usr/lib/ruby/1.8/yaml/*

What’s going on here?

Thanks,
–Dean

What is the output from % ruby -v

I know partly what is happening is making the keys for a hash as
symbols, hence symbolize_keys. Now that may have been obvious, but is
the reason why? Turns out, at least for me it was not obvious that a
String key and a symbol key of the same name are not equivalent, that is
they don’t hash equally. So, I believe this is part of the equation,
wish I knew more. Hope this leads to getting help.