Removed rash integration again and backported raco call.

tests/engine.rkt

@@ -8,30 +8,34 @@
 
 (dynamic-wind
   void
-  (lambda ()
+  (λ ()
     (parameterize ([current-directory tmp]
                    [current-command-line-arguments #()])
       (call-with-output-file "input.txt"
-        (lambda (out) (display "one" out)))
+        (λ (out) (display "one" out)))
 
       (define build-count 0)
 
-      (reset-makefile!)
-      (set-default-target! 'all)
-      (mark-phony! 'all)
+      (reset-makefiles!)
+      (begin-makefile! 'demo)
+      (set-default-target! 'demo 'all)
+      (mark-phony! 'demo 'all)
 
       (register-target!
+       'demo
        "result.txt"
        '("input.txt")
-       (lambda ()
+       (λ ()
          (set! build-count (add1 build-count))
          (copy-file "input.txt" "result.txt" #t)))
 
-      ;; A dependency expression may produce a list. The engine flattens it.
-      (register-target! 'all
-                        (list (list "result.txt"))
-                        void)
+      (register-target!
+       'demo
+       'all
+       (list (list "result.txt"))
+       void)
 
+      (current-makefile-prefix 'demo)
       (make-targets!)
       (check-equal? build-count 1)
       (check-true (file-exists? "result.txt"))
@@ -45,5 +49,5 @@
       (file-or-directory-modify-seconds "input.txt" (+ result-time 2))
       (make-targets!)
       (check-equal? build-count 2)))
-  (lambda ()
+  (λ ()
     (delete-directory/files tmp #:must-exist? #f)))