tenderlove/psych — pull request #57 by gryphis (2012-04-07 10:57:49+00:00)
Title: Solve an error using 'rails db'

Calling 'rails db' causes ==>

/home/akt/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:221:in `merge!': can't convert nil into Hash (TypeError)

Line 221 at my version equates to line 257 at the version I patch here.
Applying my patch the error removed and the console opened.