Compile time error on invalid code: DERIVE-AREF-TYPE

(lambda ()
  (loop for lv3 below 3
        sum (sbit
             (signum
              lv3))))

==>

The value
  #<SB-KERNEL:NUMERIC-TYPE (INTEGER -1 -1)>
is not of type
  SB-KERNEL:ARRAY-TYPE
   [Condition of type TYPE-ERROR]

Restarts:
 0: [RETRY] Retry SLIME REPL evaluation request.
 1: [*ABORT] Return to SLIME's top level.
 2: [ABORT] abort thread (#<THREAD tid=2203 "new-repl-thread" RUNNING {1001110003}>)

Backtrace:
  0: (SB-C::DERIVE-AREF-TYPE #<SB-C::LVAR 1 {10373A5643}>)
  1: ((FLET SB-C::PROCESS-INFO :IN SB-C::IR1-OPTIMIZE-COMBINATION))
  2: (SB-C::IR1-OPTIMIZE-COMBINATION #<SB-C::COMBINATION :FUN #<SB-C::REF :LEAF #<SB-C::GLOBAL-VAR :%SOURCE-NAME AREF :TYPE #1=#<SB-KERNEL:FUN-TYPE #> :DEFINED-TYPE #1# :WHERE-FROM :DECLARED :KIND :GLOBAL..
  3: (SB-C::IR1-OPTIMIZE #<SB-C:COMPONENT :NAME "<unknown>" :REANALYZE T {10373A78F3}> NIL)
  4: (SB-C::IR1-OPTIMIZE-UNTIL-DONE #<SB-C:COMPONENT :NAME "<unknown>" :REANALYZE T {10373A78F3}>)
  5: (SB-C::IR1-OPTIMIZE-PHASE-1 #<SB-C:COMPONENT :NAME "<unknown>" :REANALYZE T {10373A78F3}>)
  6: (SB-C::IR1-PHASES #<SB-C:COMPONENT :NAME "<unknown>" :REANALYZE T {10373A78F3}>)
 [...]

x86-64, "2.3.9.56-6b0e43beb"