Not sure whats going on here, or what could be the integer in this case. Here's the code:

def build_array_from_file(filename)
    contents = []
    File.read(File.expand_path('lib/project_euler/' + filename), 'r') do |file|
      while line = file.get
        contents << line
      end
    end
    contents
  end

filename is a string and I've checked to make sure the path comes up valid.

Any thoughts? Thanks.