can't tell the size of #<SB-C:TN '#\0!1 :CONSTANT> (with THE of SATISFIES type)

(lambda ()
  (count-if
   #'(lambda (x) (eql x (the (satisfies eval) #\0)))
   "001011101101"))

==>

can't tell the size of #<SB-C:TN '#\0!1 :CONSTANT>
   [Condition of type SIMPLE-ERROR]

Restarts:
 0: [RETRY] Retry SLIME REPL evaluation request.
 1: [*ABORT] Return to SLIME's top level.
 2: [ABORT] abort thread (#<THREAD tid=24093 "repl-thread" RUNNING {10082D49D3}>)

Backtrace:
  0: (SB-X86-64-ASM::OPERAND-SIZE #<SB-C:TN '#\0!1 :CONSTANT>)
  1: (SB-X86-64-ASM::MATCHING-OPERAND-SIZE #<SB-C:TN '#\0!1 :CONSTANT> RSI)
  2: ((FLET SB-X86-64-ASM::EMIT* :IN "SYS:SRC;COMPILER;X86-64;INSTS.LISP") "CMP" #<SB-ASSEM:SEGMENT {100ABECC33}> 0 #<SB-C:TN '#\0!1 :CONSTANT> RSI 7)
  3: (SB-ASSEM::%ASSEMBLE #<SB-ASSEM:SEGMENT {100ABECC33}> (#<SB-ASSEM::STMT IGNORE {100ABEB413}> . #<SB-ASSEM::STMT .ALIGN {100ABECD73}>))
  4: (SB-ASSEM:ASSEMBLE-SECTIONS #S(SB-ASSEM::ASMSTREAM :DATA-SECTION (#<SB-ASSEM::STMT IGNORE {100ABEB413}> . #<SB-ASSEM::STMT .ALIGN {100ABECD73}>) :CODE-SECTION (#1=#<SB-ASSEM::STMT IGNORE {100ABEB453}>..
  5: (SB-C::GENERATE-CODE #<SB-C:COMPONENT :NAME "<unknown>" {100ABD3F13}>)
  6: (SB-C::%COMPILE-COMPONENT #<SB-C:COMPONENT :NAME "<unknown>" {100ABD3F13}>)
 [...]

x86-64, "2.3.8.173-0b334c9de"

Simplifies to

(lambda (x) (eql x (the (satisfies eval) #\0)))