ECL, defining the expander before DEFUN.
Now calling the SETF function works but it also seems
to no longer rely on our custom expander MACRO.

> (load "/tmp/setf-test")

;;; Loading #P"/tmp/setf-test.fas"
#P"/tmp/setf-test.fas"
> (test)

1
> (get-setf-expansion '(foo-val *foo*))

(#:G110)
(*FOO*)
(#:G111)
(FUNCALL #'(SETF FOO-VAL) #:G111 #:G110)
(FOO-VAL #:G110)
> (setf (foo-val *foo*) 2)

2
> *foo*

(2)
> ^D

SBCL, defining the expander before DEFUN

behemoth$ sbcl
Couldn't stat /proc/curproc/file; is /proc mounted?
This is SBCL 1.0.30, an implementation of ANSI Common Lisp.
More information about SBCL is available at <http://www.sbcl.org/>.

SBCL is free software, provided as is, with absolutely no warranty.
It is mostly in the public domain; some portions are provided under
BSD-style licenses.  See the CREDITS and COPYING files in the
distribution for more information.
Couldn't stat /proc/curproc/file; is /proc mounted?
* (load "/tmp/setf-test.lisp")

T
* (get-setf-expansion '(foo-val *foo*))

(#:G640)
(*FOO*)
(#:G641)
(FOO-VAL-SETF-SETTER-MACRO #:G641 #:G640)
(FOO-VAL-SETF-GETTER-MACRO #:G641)
* (setf (foo-val *foo*) 3)

3
* (test)

1