gnu: linux-libre-headers: Do not retain reference to the bootstrap tools.

* gnu/packages/linux.scm (linux-libre-headers)[install-phase]: Remove
  ".install" files from the output.
  [arguments]: Add #:allowed-references.

gnu/packages/linux.scm

@@ -106,12 +106,21 @@
                (and (zero? (system* "make"
                                     (string-append "INSTALL_HDR_PATH=" out)
                                     "headers_install"))
-                    (mkdir (string-append out "/include/config"))
-                    (call-with-output-file
-                        (string-append out
-                                       "/include/config/kernel.release")
-                      (lambda (p)
-                        (format p "~a-default~%" ,version))))))))
+                    (begin
+                      (mkdir (string-append out "/include/config"))
+                      (call-with-output-file
+                          (string-append out
+                                         "/include/config/kernel.release")
+                        (lambda (p)
+                          (format p "~a-default~%" ,version)))
+
+                      ;; Remove the '.install' and '..install.cmd' files; the
+                      ;; latter contains store paths, which pulls in bootstrap
+                      ;; binaries in the build environment, and prevents bit
+                      ;; reproducibility for the bootstrap binaries.
+                      (for-each delete-file (find-files out "\\.install"))
+
+                      #t))))))
    (package
     (name "linux-libre-headers")
     (version version)
@@ -133,6 +142,7 @@
                  (alist-replace
                   'install ,install-phase
                   (alist-delete 'configure %standard-phases)))
+       #:allowed-references ()
        #:tests? #f))
     (synopsis "GNU Linux-Libre kernel headers")
     (description "Headers of the Linux-Libre kernel.")

gnu/packages/make-bootstrap.scm

@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2012, 2013, 2014 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2012, 2013, 2014, 2015 Ludovic Courtès <ludo@gnu.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -374,10 +374,6 @@ for `sh' in $PATH, and without nscd, and with static NSS modules."
              (copy-recursively (string-append linux "/include/asm-generic")
                                (string-append incdir "/asm-generic"))
 
-             ;; Remove the '.install' and '..install.cmd' files; the latter
-             ;; contains store paths, which prevents bit reproducibility.
-             (for-each delete-file (find-files incdir "\\.install"))
-
              #t))))
       (inputs `(("libc" ,(let ((target (%current-target-system)))
                            (if target