Environments can't handle multiple entries with the same name about clasp HOT 6 CLOSED

CL-USER> (let* ((x 1)
                (x (+ 1 x)))
           (print x))

The symbol[X] is already in the environment
   [Condition of type SIMPLE-PROGRAM-ERROR]

Restarts:
 0: [RETRY] Retry SLIME REPL evaluation request.
 1: [*PROCESS-INPUT] Continue reading input.
 2: [ABORT] Return to SLIME's top level.
 3: [CLOSE-CONNECTION] Close SLIME connection.
 4: [RESTART-TOPLEVEL] Go back to Top-Level REPL.

Backtrace:
  0: (CORE::UNNAMED-LAMBDA #<COMMON-LISP:COMPILED-FUNCTION CORE::UNNAMED-LAMBDA CompiledClosure>)
  1: (APPLY #<COMMON-LISP:COMPILED-FUNCTION CORE::UNNAMED-LAMBDA CompiledClosure> #<COMMON-LISP:COMPILED-FUNCTION CORE::UNNAMED-LAMBDA CompiledClosure> NIL)
  2: (SWANK/BACKEND:CALL-WITH-DEBUGGING-ENVIRONMENT #<COMMON-LISP:COMPILED-FUNCTION CORE::UNNAMED-LAMBDA CompiledClosure>)
  3: (TOP-LEVEL)
  4: (CALL-WITH-VARIABLE-BOUND SWANK::*SLDB-STEPPING-P* NIL #<COMMON-LISP:COMPILED-FUNCTION CORE:TOP-LEVEL CompiledClosure>)
  5: (TOP-LEVEL)
  6: (CALL-WITH-VARIABLE-BOUND SWANK::*SLDB-LEVEL* 1 #<COMMON-LISP:COMPILED-FUNCTION CORE:TOP-LEVEL CompiledClosure>)
  7: (TOP-LEVEL)
  8: (CALL-WITH-VARIABLE-BOUND *PACKAGE* #<COMMON-LISP-USER> #<COMMON-LISP:COMPILED-FUNCTION CORE:TOP-LEVEL CompiledClosure>)
  9: (TOP-LEVEL)
 10: (CALL-WITH-VARIABLE-BOUND SWANK:*SLDB-QUIT-RESTART* #<RESTART.2120592393> #<COMMON-LISP:COMPILED-FUNCTION CORE:TOP-LEVEL CompiledClosure>)
 11: (TOP-LEVEL)
 12: (CALL-WITH-VARIABLE-BOUND SWANK::*SLDB-RESTARTS* (#<RESTART.2121942409> #<RESTART.2120592393> #<RESTART.2120272201> #<RESTART.2139755337> #<RESTART.2054272137>) #<COMMON-LISP:COMPILED-FUNCTION CORE:TO..
 13: (TOP-LEVEL)
 14: (CALL-WITH-VARIABLE-BOUND SWANK::*SWANK-DEBUGGER-CONDITION* #<CORE:SIMPLE-PROGRAM-ERROR @0x7fb47e7b8e09> #<COMMON-LISP:COMPILED-FUNCTION CORE:TOP-LEVEL CompiledClosure>)
 15: (SWANK::DEBUG-IN-EMACS #<CORE:SIMPLE-PROGRAM-ERROR @0x7fb47e7b8e09>)
 16: (TOP-LEVEL)
 17: (CALL-WITH-VARIABLE-BOUND SWANK::*SLIME-INTERRUPTS-ENABLED* NIL #<COMMON-LISP:COMPILED-FUNCTION CORE:TOP-LEVEL CompiledClosure>)
 18: (CORE::UNNAMED-LAMBDA)
 19: (MULTIPLE-VALUE-PROG1-FUNCTION #<COMMON-LISP:COMPILED-FUNCTION CORE::UNNAMED-LAMBDA CompiledClosure> #<COMMON-LISP:COMPILED-FUNCTION CORE::UNNAMED-LAMBDA CompiledClosure>)
 20: (SWANK:INVOKE-SLIME-DEBUGGER #<CORE:SIMPLE-PROGRAM-ERROR @0x7fb47e7b8e09>)
 21: (CORE::UNNAMED-LAMBDA)
 22: (FUNCALL #<COMMON-LISP:COMPILED-FUNCTION CORE::UNNAMED-LAMBDA CompiledClosure>)
 23: (TOP-LEVEL)
 24: (CALL-WITH-VARIABLE-BOUND EXT:*INVOKE-DEBUGGER-HOOK* #<COMMON-LISP:COMPILED-FUNCTION CORE::UNNAMED-LAMBDA CompiledClosure> #<COMMON-LISP:COMPILED-FUNCTION CORE:TOP-LEVEL CompiledClosure>)
 25: (TOP-LEVEL)
 26: (CALL-WITH-VARIABLE-BOUND *DEBUGGER-HOOK* #<COMMON-LISP:COMPILED-FUNCTION SWANK:SWANK-DEBUGGER-HOOK CompiledClosure> #<COMMON-LISP:COMPILED-FUNCTION CORE:TOP-LEVEL CompiledClosure>)
 27: (CORE::UNNAMED-LAMBDA #<COMMON-LISP:COMPILED-FUNCTION CORE::UNNAMED-LAMBDA CompiledClosure> #<COMMON-LISP:COMPILED-FUNCTION SWANK:SWANK-DEBUGGER-HOOK CompiledClosure>)
 28: (APPLY #<COMMON-LISP:COMPILED-FUNCTION CORE::UNNAMED-LAMBDA CompiledClosure> #<COMMON-LISP:COMPILED-FUNCTION SWANK:SWANK-DEBUGGER-HOOK CompiledClosure> #<COMMON-LISP:COMPILED-FUNCTION CORE::UNNAMED-LA..
 29: (SWANK/BACKEND:CALL-WITH-DEBUGGER-HOOK #<COMMON-LISP:COMPILED-FUNCTION SWANK:SWANK-DEBUGGER-HOOK CompiledClosure> #<COMMON-LISP:COMPILED-FUNCTION CORE::UNNAMED-LAMBDA CompiledClosure>)
 30: (TOP-LEVEL)
 31: (CALL-WITH-VARIABLE-BOUND CORE::*HANDLER-CLUSTERS* (((SWANK::INVOKE-DEFAULT-DEBUGGER . #<COMMON-LISP:COMPILED-FUNCTION CORE::UNNAMED-LAMBDA CompiledClosure>)) ..) #<COMMON-LISP:COMPILED-FUNCTION CORE:..
 32: (SWANK:SWANK-DEBUGGER-HOOK #<CORE:SIMPLE-PROGRAM-ERROR @0x7fb47e7b8e09> #<COMMON-LISP:COMPILED-FUNCTION SWANK:SWANK-DEBUGGER-HOOK CompiledClosure>)
 33: (FUNCALL #<COMMON-LISP:COMPILED-FUNCTION SWANK:SWANK-DEBUGGER-HOOK CompiledClosure> #<CORE:SIMPLE-PROGRAM-ERROR @0x7fb47e7b8e09> #<COMMON-LISP:COMPILED-FUNCTION SWANK:SWANK-DEBUGGER-HOOK CompiledClosu..
 34: (TOP-LEVEL)
 35: (CALL-WITH-VARIABLE-BOUND *DEBUGGER-HOOK* NIL #<COMMON-LISP:COMPILED-FUNCTION CORE:TOP-LEVEL CompiledClosure>)
 36: (INVOKE-DEBUGGER #<CORE:SIMPLE-PROGRAM-ERROR @0x7fb47e7b8e09>)
 37: (UNIVERSAL-ERROR-HANDLER NIL SIMPLE-PROGRAM-ERROR (:FORMAT-CONTROL "The symbol[X] is already in the environment" :FORMAT-ARGUMENTS NIL))
 38: (ERROR #<COMMON-LISP:FUNCTION COMMON-LISP:ERROR VariadicFunctoid> SIMPLE-PROGRAM-ERROR :FORMAT-CONTROL "The symbol[X] is already in the environment" :FORMAT-ARGUMENTS)
 39: (APPLY #<COMMON-LISP:FUNCTION COMMON-LISP:ERROR VariadicFunctoid> SIMPLE-PROGRAM-ERROR :FORMAT-CONTROL "The symbol[X] is already in the environment" :FORMAT-ARGUMENTS NIL NIL)
 40: (SIGNAL-SIMPLE-ERROR PROGRAM-ERROR NIL "The symbol[X] is already in the environment" NIL)
 41: (EVAL (LET* ((X 1) (X (+ 1 X))) ..))
 --more--

> (let* ((x 1)
       (x (+ 1 x)))
  (print x))

2 
2

Starting Boehm cclasp 0.3-test-10-159-g2e97cc5 ... loading image... it takes a few seconds
Top level.
> (let* ((x 1)
       (x (+ 1 x)))
  (print x))

2 
2
> (eval '(let* ((x 1)
       (x (+ 1 x)))
  (print x)))

Condition of type: SIMPLE-PROGRAM-ERROR
The symbol[X] is already in the environment

> (let* ((x 1)
       (x (+ 1 x)))
  (print x))

2 
2
> (eval '(let* ((x 1)
       (x (+ 1 x)))
  (print x)))

2 
2