Passing Structs by Value using cffi-libffi doesn't work well

[clsper03]

C codes in the file test.c as below:
struct complex {
  double real;
  double imag;
};
double magnitude_squared (struct complex c) {
  return c.real * c.real + c.imag * c.imag;
};

Compile this into a shared library:
gcc -fpic -shared test.c -o test.so

then typing in REPL:
shows below:

CFFI-LIBFFI-TEST> (ql:quickload :cffi-libffi)
To load "cffi-libffi":
  Load 1 ASDF system:
    cffi-libffi
; Loading "cffi-libffi"

(:CFFI-LIBFFI)
CFFI-LIBFFI-TEST> (cffi:load-foreign-library "/root/code/cffi-libffi-test/test.so")
#<CFFI:FOREIGN-LIBRARY TEST.SO-653 "test.so">
CFFI-LIBFFI-TEST> (cffi:defcstruct c-complex
(real :double)
(imag :double))
(:STRUCT C-COMPLEX)
CFFI-LIBFFI-TEST> (cffi:defcfun ("magnitude_squared" ms) :double
(c (:struct c-complex)))
WARNING: redefining CFFI-LIBFFI-TEST::MS in DEFUN
MS
CFFI-LIBFFI-TEST> (cffi:with-foreign-object (c '(:struct c-complex))
(setf (cffi:foreign-slot-value c '(:struct c-complex)
'real)
3d0
(cffi:foreign-slot-value c '(:struct c-complex)
'imag)
4d0)
(sqrt (ms c)))

Then comes with error:
There is no applicable method for the generic function
  #<STANDARD-GENERIC-FUNCTION CFFI:TRANSLATE-INTO-FOREIGN-MEMORY (5)>
when called with arguments
  (#.(SB-SYS:INT-SAP #X7F51FF2B7FE8)
   #<C-COMPLEX-TCLASS C-COMPLEX>
   #.(SB-SYS:INT-SAP #X7F51FF2B7FC8)).
   [Condition of type SB-PCL::NO-APPLICABLE-METHOD-ERROR]
See also:
  Common Lisp Hyperspec, 7.6.6 [:section]

Restarts:
 0: [RETRY] Retry calling the generic function.
 1: [RETRY] Retry SLIME REPL evaluation request.
 2: [*ABORT] Return to SLIME's top level.
 3: [ABORT] abort thread (#<THREAD "repl-thread" RUNNING {1003039B63}>)
.

And I have tested that the subsystem CFFI-LIBFFI has been loaded and I have installed LIBFFI and it works well.
cffi_0.24.1 + SBCL 1.4.16.debian x8664 + GNU Emacs 26.1 + slime