transformations: Preserve transformation order in package property.

Fixes <https://issues.guix.gnu.org/54942>.
Reported by SeerLite <seerlite@nixnet.email>.

* guix/transformations.scm (options->transformation)
[package-with-transformation-properties]: Add call to 'reverse'.
* tests/transformations.scm ("options->transformation, property order"):
New test.

2 files changed, 14 insertions, 2 deletions

diff --git a/guix/transformations.scm b/guix/transformations.scm
index a0045e5b272..411c4014cb7 100644
--- a/guix/transformations.scm
+++ b/guix/transformations.scm
@@ -959,7 +959,7 @@ to that transformation."
                      . ,(map (match-lambda
                                ((key value _)
                                 (cons key value)))
-                             applicable))
+                             (reverse applicable))) ;preserve order
                     ,@(package-properties p)))))
 
   (lambda (obj)
diff --git a/tests/transformations.scm b/tests/transformations.scm
index 8db85b4305b..dbfe5235188 100644
--- a/tests/transformations.scm
+++ b/tests/transformations.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2016, 2017, 2019, 2020, 2021 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2016-2017, 2019-2022 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2021 Marius Bakke <marius@gnu.org>
 ;;;
 ;;; This file is part of GNU Guix.
@@ -451,6 +451,18 @@
                              (string=? (local-file-file input) patch)))
                       inputs))))))))
 
+(test-equal "options->transformation, property order"
+  ;; See <https://issues.guix.gnu.org/54942>.
+  '((with-debug-info . "does-not-exist")
+    (with-commit . "does-not-exist=aaaaaaa")
+    (without-tests . "does-not-exist"))
+  (let* ((t (options->transformation
+             '((with-debug-info . "does-not-exist")
+               (with-commit . "does-not-exist=aaaaaaa")
+               (without-tests . "does-not-exist")))))
+    (let ((new (t coreutils)))
+      (assq-ref (package-properties new) 'transformations))))
+
 (test-equal "options->transformation, with-latest"
   "42.0"
   (mock ((guix upstream) %updaters