$ cat x.scm
(declare (unit m))
(module m (f)
 (import chicken scheme)
 (define (f x) (- x)))
$ cat y.scm
(declare (uses m))
(module y (main)
 (import chicken scheme)
 (import m)
 (define (main) (f 1))
 (print (main)))
$ csc -c -J x.scm && csc y.scm -prologue m.import.scm x.o
$ ./y
-1