Comment 5 for bug 1308328

This bug pops up in the random tester (SBCL 1.2.5):

(defparameter *f3*
  '(lambda (a c)
    (declare (type (integer 104233 622985) a))
    (declare (type (integer -54069182 937) c))
    (declare (ignorable a c))
    (declare
     (optimize (speed 2) (space 3) (safety 2) (debug 0)
      (compilation-speed 3)))
    (block b1
      (prog1
   (let* ((*s4*
    (the integer
      (return-from b1 a))
     ))
       (declare (dynamic-extent *s4*))
       0)
 ))))

#|

* (compile nil *f3*)

debugger invoked on a SB-INT:BUG in thread
#<THREAD "main thread" RUNNING {1003016813}>:
    failed AVER:
      (AND (EQ (CTRAN-KIND START) INSIDE-BLOCK) (NOT (BLOCK-DELETE-P BLOCK)))
  This is probably a bug in SBCL itself. (Alternatively, SBCL might have been
  corrupted by bad user code, e.g. by an undefined Lisp operation like
  (FMAKUNBOUND 'COMPILE), or by stray pointers from alien code or from unsafe
  Lisp code; or there might be a bug in the OS or hardware that SBCL is running
  on.) If it seems to be a bug in SBCL itself, the maintainers would like to
  know about it. Bug reports are welcome on the SBCL mailing lists, which you
  can find at <http://sbcl.sourceforge.net/>.

Type HELP for debugger help, or (SB-EXT:EXIT) to exit from SBCL.

restarts (invokable by number or by possibly-abbreviated name):
  0: [ABORT] Exit debugger, returning to top level.

(SB-INT:BUG "~@<failed AVER: ~2I~_~A~:>" (AND (EQ (SB-C::CTRAN-KIND SB-C::START) :INSIDE-BLOCK) (NOT (SB-C::BLOCK-DELETE-P BLOCK))))
0]