derivations: Introduce 'graft' record type.

* guix/derivations.scm (<graft>): New record type.
  (graft-derivation): Rename 'replacements' to 'grafts', and expect it
  to be a list of <graft> records.  Adjust accordingly.
* tests/derivations.scm ("graft-derivation"): Use 'graft' instead of
  pairs in argument to 'graft-derivation'.

1 files changed, 6 insertions, 2 deletions

diff --git a/tests/derivations.scm b/tests/derivations.scm
index 48d12990e6..e774fed4c3 100644
--- a/tests/derivations.scm
+++ b/tests/derivations.scm
@@ -831,8 +831,12 @@ Deriver: ~a~%"
                                                  (lambda (port)
                                                    (display "fake mkdir" port)))))
          (graft (graft-derivation %store "graft" orig
-                                  `(((,%bash) . (,one))
-                                    ((,%mkdir) . (,two))))))
+                                  (list (graft
+                                          (origin %bash)
+                                          (replacement one))
+                                        (graft
+                                          (origin %mkdir)
+                                          (replacement two))))))
     (and (build-derivations %store (list graft))
          (let ((two   (derivation->output-path two))
                (graft (derivation->output-path graft)))