[bug#48806,5/7] store: Remove 'references/substitutes'.

diff --git a/guix/store.scm b/guix/store.scm
index 38d12ac5d7..ea784a33d2 100644
--- a/guix/store.scm
+++ b/guix/store.scm
@@ -148,7 +148,6 @@ 
             built-in-builders
             references
             references/cached
-            references/substitutes
             references*
             query-path-info*
             requisites
@@ -1481,7 +1480,7 @@  error if there is no such root."
   ;; Brute-force cache mapping store items to their list of references.
   ;; Caching matters because when building a profile in the presence of
   ;; grafts, we keep calling 'graft-derivation', which in turn calls
-  ;; 'references/substitutes' many times with the same arguments.  Ideally we
+  ;; 'references/cached' many times with the same arguments.  Ideally we
   ;; would use a cache associated with the daemon connection instead (XXX).
   (make-hash-table 100))
 
@@ -1492,58 +1491,6 @@  error if there is no such root."
         (hash-set! %reference-cache item references)
         references)))
 
-(define (references/substitutes store items)
-  "Return the list of list of references of ITEMS; the result has the same
-length as ITEMS.  Query substitute information for any item missing from the
-store at once.  Raise a '&store-protocol-error' exception if reference
-information for one of ITEMS is missing."
-  (let* ((requested  items)
-         (local-refs (map (lambda (item)
-                            (or (hash-ref %reference-cache item)
-                                (guard (c ((store-protocol-error? c) #f))
-                                  (references store item))))
-                          items))
-         (missing    (fold-right (lambda (item local-ref result)
-                                   (if local-ref
-                                       result
-                                       (cons item result)))
-                                 '()
-                                 items local-refs))
-
-         ;; Query all the substitutes at once to minimize the cost of
-         ;; launching 'guix substitute' and making HTTP requests.
-         (substs     (if (null? missing)
-                         '()
-                         (substitutable-path-info store missing))))
-    (when (< (length substs) (length missing))
-      (raise (condition (&store-protocol-error
-                         (message "cannot determine \
-the list of references")
-                         (status 1)))))
-
-    ;; Intersperse SUBSTS and LOCAL-REFS.
-    (let loop ((items       items)
-               (local-refs  local-refs)
-               (result      '()))
-      (match items
-        (()
-         (let ((result (reverse result)))
-           (for-each (cut hash-set! %reference-cache <> <>)
-                     requested result)
-           result))
-        ((item items ...)
-         (match local-refs
-           ((#f tail ...)
-            (loop items tail
-                  (cons (any (lambda (subst)
-                               (and (string=? (substitutable-path subst) item)
-                                    (substitutable-references subst)))
-                             substs)
-                        result)))
-           ((head tail ...)
-            (loop items tail
-                  (cons head result)))))))))
-
 (define* (fold-path store proc seed paths
                     #:optional (relatives (cut references store <>)))
   "Call PROC for each of the RELATIVES of PATHS, exactly once, and return the
diff --git a/tests/store.scm b/tests/store.scm
index 9c25adf5e9..3266fa7a82 100644
--- a/tests/store.scm
+++ b/tests/store.scm
@@ -308,42 +308,6 @@ 
          (null? (references %store t1))
          (null? (referrers %store t2)))))
 
-(test-assert "references/substitutes missing reference info"
-  (with-store s
-    (set-build-options s #:use-substitutes? #f)
-    (guard (c ((store-protocol-error? c) #t))
-      (let* ((b  (add-to-store s "bash" #t "sha256"
-                               (search-bootstrap-binary "bash"
-                                                        (%current-system))))
-             (d  (derivation s "the-thing" b '("--help")
-                             #:inputs `((,b)))))
-        (references/substitutes s (list (derivation->output-path d) b))
-        #f))))
-
-(test-assert "references/substitutes with substitute info"
-  (with-store s
-    (set-build-options s #:use-substitutes? #t)
-    (let* ((t1 (add-text-to-store s "random1" (random-text)))
-           (t2 (add-text-to-store s "random2" (random-text)
-                                  (list t1)))
-           (t3 (add-text-to-store s "build" "echo -n $t2 > $out"))
-           (b  (add-to-store s "bash" #t "sha256"
-                             (search-bootstrap-binary "bash"
-                                                      (%current-system))))
-           (d  (derivation s "the-thing" b `("-e" ,t3)
-                           #:inputs `((,b) (,t3) (,t2))
-                           #:env-vars `(("t2" . ,t2))))
-           (o  (derivation->output-path d)))
-      (with-derivation-narinfo d
-        (sha256 => (gcrypt:sha256 (string->utf8 t2)))
-        (references => (list t2))
-
-        (equal? (references/substitutes s (list o t3 t2 t1))
-                `((,t2)                           ;refs of O
-                  ()                              ;refs of T3
-                  (,t1)                           ;refs of T2
-                  ()))))))                        ;refs of T1
-
 (test-equal "substitutable-path-info when substitutes are turned off"
   '()
   (with-store s