Usage: wtf[?|!]
      Show's a few lines of the backtrace of the most recent exception (also available
      as `_ex_.backtrace`). If you want to see more lines, add more question marks or
      exclamation marks.
      wtf?
      wtf?!???!?!?

Source: pry/wtf.rb at d6ef67cfa7cd5ff2b6da5aa2c9946969c033b105 pry/pry

If you want to see more lines, add more question marks or exclamation marks.

Ha!