Comment 1 for bug 521153

The current SBCL requires (debug 3) to trigger this, and this is caused by pretty-printing source forms:
https://github.com/sbcl/sbcl/blob/master/src/compiler/ir1tran.lisp#L1002

With (*print-pretty* t):

(time (test '(debug 3)))

Evaluation took:
  17.911 seconds of real time
  17.917119 seconds of total run time (17.193074 user, 0.724045 system)
  [ Run times consist of 0.172 seconds GC time, and 17.746 seconds non-GC time. ]
  100.03% CPU
  3 forms interpreted
  4 lambdas converted
  58,958,048,025 processor cycles
  2 page faults
  4,298,954,016 bytes consed

With (*print-pretty* nil):

(time (test '(debug 3)))

Evaluation took:
  1.038 seconds of real time
  1.036065 seconds of total run time (1.008063 user, 0.028002 system)
  [ Run times consist of 0.016 seconds GC time, and 1.021 seconds non-GC time. ]
  99.81% CPU
  3 forms interpreted
  4 lambdas converted
  3,417,529,794 processor cycles
  318,339,648 bytes consed