Spree installation issue : rake aborted! couldn't parse YAML at line 6 column 50

I am trying to install the spree gem using the following instructions http://spreecommerce.com/resources/qui开发者_如何学Cck-start

I am getting following error on step 4.6(Populating the Database)

    $ rake db:bootstrap
    .....
    .......
    rake aborted! 
    couldn't parse YAML at line 6 column 50
    ....
    .....

I am using ruby 1.9.2p0, rails 3.0.3 and spree 0.40.2.

Can anyone please tell me what could be the problem?

There's probably an error in a YAML file, not surprisingly. It's likely a fixture used in the bootstrapping process.

You can always run rake with the --trace option to get a better sense of what it was trying to do. Have a look through your fixture files to see if any are invalid, especially at the position indicated.

In boot.rb file inside config directory of my rails project home I added following and it worked.

require 'yaml'
YAML::ENGINE.yamler= 'syck'

I followed instruction from http://www.ruby-forum.com/topic/1002689