This is just a single example. Just run the specs to get more.

/[:stuff:]/.gen TypeError: [:stuff] is not a symbol

from /usr/local/lib/ruby1.9/gems/1.9.1/gems/randexp-0.1.5/lib/randexp/reducer.rb:97:in `randgen'
from /usr/local/lib/ruby1.9/gems/1.9.1/gems/randexp-0.1.5/lib/randexp/reducer.rb:20:in `random'
from /usr/local/lib/ruby1.9/gems/1.9.1/gems/randexp-0.1.5/lib/randexp/reducer.rb:4:in `reduce'
from /usr/local/lib/ruby1.9/gems/1.9.1/gems/randexp-0.1.5/lib/randexp.rb:9:in `reduce'
from /usr/local/lib/ruby1.9/gems/1.9.1/gems/randexp-0.1.5/lib/randexp/core_ext/regexp.rb:3:in `generate'
from (irb):5
from /usr/local/bin/irb:12:in `<main>'