gnu: Add missing module import.

This is a follow-up to commit 61fc72d3ac949d0c65690ee25bb1daf01f39bb42.

* gnu/packages/backup.scm: Add missing import of (guix build-system cmake).

diff --git a/gnu/packages/backup.scm b/gnu/packages/backup.scm
index 23860ec..692795c 100644 (file)
--- a/gnu/packages/backup.scm
+++ b/gnu/packages/backup.scm
@@ -11,7 +11,7 @@
 ;;; Copyright © 2017 Rutger Helling <rhelling@mykolab.com>
 ;;; Copyright © 2018 Mark H Weaver <mhw@netris.org>
 ;;; Copyright © 2018 Oleg Pykhalov <go.wigust@gmail.com>
-;;; Copyright © 2018, 2019 Ricardo Wurmus <rekado@elephly.net>
+;;; Copyright © 2018, 2019, 2020 Ricardo Wurmus <rekado@elephly.net>
 ;;; Copyright © 2019 Alex Vong <alexvong1995@gmail.com>
 ;;; Copyright © 2019 Marius Bakke <mbakke@fastmail.com>
 ;;; Copyright © 2020 Nicolas Goaziou <mail@nicolasgoaziou.fr>
@@ -37,6 +37,7 @@
   #:use-module (guix git-download)
   #:use-module (guix download)
   #:use-module (guix utils)
+  #:use-module (guix build-system cmake)
   #:use-module (guix build-system gnu)
   #:use-module (guix build-system go)
   #:use-module (guix build-system python)