gnu: gettext, attr, acl: Disable `check' phase twiddling when cross building.

* gnu/packages/gettext.scm (gettext)[arguments]: Disable `check' phase
  manipulations when (%current-target-system) is true.
* gnu/packages/attr.scm (attr)[arguments]: Likewise.
* gnu/packages/acl.scm (acl)[arguments]: Likewise.

gnu/packages/acl.scm

@@ -45,18 +45,30 @@
         'configure 'patch-makefile-SHELL
         (lambda _
           (patch-makefile-SHELL "include/buildmacros"))
-        (alist-replace
-         'check
-         (lambda _
-           (system* "make" "tests" "-C" "test")
+        ,(if (%current-target-system)
+             '%standard-cross-phases
+             '(alist-replace 'check
+                             (lambda _
+                               (system* "make" "tests" "-C" "test")
 
-           ;; XXX: Ignore the test result since this is
-           ;; dependent on the underlying file system.
-           #t)
-         %standard-phases))))
+                               ;; XXX: Ignore the test result since this is
+                               ;; dependent on the underlying file system.
+                               #t)
+                             %standard-phases)))))
     (inputs `(("attr" ,attr)
-              ("gettext" ,guix:gettext)
-              ("perl" ,perl)))
+
+              ;; Perl is needed to run tests; remove it from cross builds.
+              ,@(if (%current-target-system)
+                    '()
+                    `(("gettext" ,guix:gettext)
+                      ("perl" ,perl)))))
+    (native-inputs
+     ;; FIXME: Upon next core-updates, make gettext a native input
+     ;; unconditionally.
+     (if (%current-target-system)
+         `(("gettext" ,guix:gettext))
+         '()))
+
     (home-page
      "http://savannah.nongnu.org/projects/acl")
     (synopsis