pull: Use the build procedure provided by the newly-downloaded Guix.

Fixes <http://bugs.gnu.org/18534>.

* guix/scripts/pull.scm (with-environment-variable, with-PATH): New
  macros.
  (temporary-directory, first-directory, interned-then-deleted): New
  procedures.
  (unpack): Rewrite to do the unpacking in the current process rather
  than as a separate derivation.
  (%self-build-file): New variable.
  (build-from-source): New procedure.
  (build-and-install): Use it.
* guix/build/pull.scm (build-guix): Rename 'tarball' argument to
  'source'.  Remove #:tar and #:gzip parameters, as well as 'tar'
  invocation.  Remove 'scandir' invocation.  Wrap body in
  'with-directory-excursion'.
* build-aux/build-self.scm: New file.
* Makefile.am (EXTRA_DIST): Add it.

1 files changed, 98 insertions, 0 deletions

diff --git a/build-aux/build-self.scm b/build-aux/build-self.scm
new file mode 100644
index 0000000000..b78f3cb437
--- /dev/null
+++ b/build-aux/build-self.scm
@@ -0,0 +1,98 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2014 Ludovic Courtès <ludo@gnu.org>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (build-self)
+  #:use-module (gnu)
+  #:use-module (guix)
+  #:use-module (srfi srfi-1)
+  #:export (build))
+
+;;; Commentary:
+;;;
+;;; When loaded, this module returns a monadic procedure of at least one
+;;; argument: the source tree to build.  It returns a derivation that
+;;; builds it.
+;;;
+;;; This file uses modules provided by the already-installed Guix.  Those
+;;; modules may be arbitrarily old compared to the version we want to
+;;; build.  Because of that, it must rely on the smallest set of features
+;;; that are likely to be provided by the (guix) and (gnu) modules, and by
+;;; Guile itself, forever and ever.
+;;;
+;;; Code:
+
+
+;; The dependencies.  Don't refer explicitly to the variables because they
+;; could be renamed or shuffled around in modules over time.  Conversely,
+;; 'find-best-packages-by-name' is expected to always have the same semantics.
+
+(define libgcrypt
+  (first (find-best-packages-by-name "libgcrypt" #f)))
+
+(define guile-json
+  (first (find-best-packages-by-name "guile-json" #f)))
+
+
+
+;; The actual build procedure.
+
+(define (top-source-directory)
+  "Return the name of the top-level directory of this source tree."
+  (and=> (assoc-ref (current-source-location) 'filename)
+         (lambda (file)
+           (string-append (dirname file) "/.."))))
+
+;; The procedure below is our return value.
+(define* (build source #:key verbose?
+                #:allow-other-keys
+                #:rest rest)
+  "Return a derivation that unpacks SOURCE into STORE and compiles Scheme
+files."
+  (define builder
+    #~(begin
+        (use-modules (guix build pull))
+
+        (let ((json (string-append #$guile-json "/share/guile/site/2.0")))
+          (set! %load-path (cons json %load-path))
+          (set! %load-compiled-path (cons json %load-compiled-path)))
+
+        (build-guix #$output #$source
+
+                    ;; XXX: This is not perfect, enabling VERBOSE? means
+                    ;; building a different derivation.
+                    #:debug-port (if #$verbose?
+                                     (current-error-port)
+                                     (%make-void-port "w"))
+                    #:gcrypt #$libgcrypt)))
+
+  (gexp->derivation "guix-latest" builder
+                    #:modules '((guix build pull)
+                                (guix build utils))
+
+                    ;; Arrange so that our own (guix build …) modules are
+                    ;; used.
+                    #:module-path (list (top-source-directory))))
+
+;; This file is loaded by 'guix pull'; return it the build procedure.
+build
+
+;; Local Variables:
+;; eval: (put 'with-load-path 'scheme-indent-function 1)
+;; End:
+
+;;; build-self.scm ends here