--- guix.old/gnu/packages/cross-base.scm	2015-01-31 11:06:42.025984113 +0100
+++ guix/gnu/packages/cross-base.scm	2015-01-31 10:37:35.290053633 +0100
@@ -151,21 +151,33 @@
                  `(alist-cons-before
                    'configure 'set-cross-path
                    (lambda* (#:key inputs #:allow-other-keys)
-                     ;; Add the cross Linux headers to CROSS_CPATH, and remove
+                     ;; Add the cross kernel headers to CROSS_CPATH, and remove
                      ;; them from CPATH.
                      (let ((libc  (assoc-ref inputs "libc"))
                            (linux (assoc-ref inputs
-                                             "libc/cross-linux-headers")))
+                                             "libc/cross-linux-headers"))
+                           (mach  (assoc-ref inputs
+                                             "libc/cross-gnumach-headers"))
+                           (hurd  (assoc-ref inputs
+                                             "libc/cross-hurd-headers"))
+                           (hurd-minimal (assoc-ref inputs
+                                             "libc/cross-hurd-minimal")))
                        (define (cross? x)
-                         ;; Return #t if X is a cross-libc or cross Linux.
+                         ;; Return #t if X is a cross-libc or a cross-kernel.
                          (or (string-prefix? libc x)
-                             (string-prefix? linux x)))
+                             (if linux        (string-prefix? linux x) #f)
+                             (if hurd         (string-prefix? hurd  x) #f)
+                             (if mach         (string-prefix? mach  x) #f)
+                             (if hurd-minimal (string-prefix? hurd-minimal x) #f)))
 
                        (setenv "CROSS_CPATH"
-                               (string-append libc "/include:"
-                                              linux "/include"))
+                               (string-append libc "/include"
+                                              (if linux (string-append ":" linux "/include") "")
+                                              (if hurd  (string-append ":" hurd "/include"
+                                                                       ":" mach "/include")  "")))
                        (setenv "CROSS_LIBRARY_PATH"
-                               (string-append libc "/lib"))
+                               (string-append libc "/lib"
+                                              (if hurd-minimal (string-append ":" hurd-minimal "/lib") "")))
 
                        (let ((cpath   (search-path-as-string->list
                                        (getenv "CPATH")))