gistfile1.txt

from /lib/active_record/fixtures.rb (code is the same in 2.3.2 and 2.3.3)

    def parse_yaml_string(fixture_content)
      YAML::load(erb_render(fixture_content))
    rescue => error
      raise Fixture::FormatError, "a YAML error occurred parsing #{yaml_file_path}. Please note that YAML must be consistently indented using spaces. Tabs are not allowed. Please have a look at http://www.yaml.org/faq.html\nThe exact error was:\n  #{error.class}: #{error}"
    end

    def erb_render(fixture_content)
      ERB.new(fixture_content).result
    end