# File lib/rspec/core/memoized_helpers.rb, line 115
        def fetch(key, &block)
          description = if key == :subject
            "subject"
          else
            "let declaration `#{key}`"
          end

          ::RSpec.warn_deprecation "WARNING: \#{description} accessed in a `before(:all)` hook at:\n\#{caller[1]}\n\nThis is deprecated behavior that will not be supported in RSpec 3.\n\n`let` and `subject` declarations are not intended to be called\nin a `before(:all)` hook, as they exist to define state that\nis reset between each example, while `before(:all)` exists to\ndefine state that is shared across examples in an example group.\n"

          @hash.fetch(key, &block)
        end