* guix/import/elpa.scm (latest-release, package-from-gnu.org?): New
  procedures.
  (%elpa-updater): New variable.
* guix/scripts/refresh.scm (%updaters): Add %ELPA-UPDATER.

* guix/import/elpa.scm (elpa-fetch-archive): Set %HTTP-CACHE-TTL to 6
  hours.
  (call-with-downloaded-file): Use 'http-fetch/cached' instead of
  'url-fetch'.

* guix/gnu-maintenance.scm (<gnu-release>): Remove.
  (coalesce-releases): Move to upstream.scm.  Rename to
  'coalesce-sources'; adjust callers.
  (releases, latest-release): Return <upstream-source> objects instead
  of <gnu-release> objects.
  (latest-release*, non-emacs-gnu-package?): New procedures.
  (gnu-release-archive-types): Remove.
  (%gnu-updater): New variable.
  (package-update-path, download-tarball, package-update,
  update-package-source): Move to...
* guix/upstream.scm: ... here.  New file.
* Makefile.am (MODULES): Add it.
* po/guix/POTFILES.in: Replace gnu-maintenance.scm with upstream.scm.
* guix/scripts/refresh.scm (%updaters): New variable.
  (update-package): Adjust to new 'package-update' interface.
  (guix-refresh): Adjust to new 'package-update-path'.  Remove
  'false-if-exception' around it.

Fixes a typo in commit 739ab68b that made it a procedure returning a
parameter.

* guix/http-client.scm (%http-cache-ttl): Turn into a parameter.

* gnu/packages/wm.scm (evilwm): New variable.

* gnu/services/xorg.scm (xorg-configuration-file): Add font-alias directories
  to xserver.conf FontPath.

* gnu/packages/xorg.scm (font-alias)[arguments]: New 'install-fonts-dir'
  phase.

* gnu/packages/xorg.scm (xlsfonts): New variable.

This reverts commit a5d06c0c.

This reverts commit 075c3ebd.

* gnu/packages/image.scm (giflib): Update to 5.1.1.

* gnu/packages/gnunet.scm (gnurl): Update to 7.45.0.

* gnu/packages/curl.scm (curl): Update to 7.45.0.

* emacs/guix-devel.el: Add indentation rules for 'modify-phases' keywords.
  (guix-devel-indent-modify-phases-keyword,
  guix-devel-indent-modify-phases-keyword-1,
  guix-devel-indent-modify-phases-keyword-2): New functions.

* emacs/guix-config.el.in (guix-emacs-interface-directory,
  guix-state-directory): Rename to ...
  (guix-config-emacs-interface-directory, guix-config-state-directory):
  ...this.
  (guix-config-guile-program): New constant.
  (guix-guile-program): Move to ...
* emacs/guix-external.el (guix-guile-program): ...here.  Make it a
  'defcustom'.
* emacs/guix-profiles.el (guix-default-profile): Use
  'guix-config-state-directory'.
* emacs/guix-backend.el (guix-load-path): Use
  'guix-config-emacs-interface-directory'.

Suggested by Ludovic Courtès <ludo@gnu.org>.

* configure.ac: Set DOT_USER_PROGRAM variable.
* emacs/guix-config.el.in (guix-config-dot-program): New constant.
* emacs/guix-external.el (guix-dot-program): Use it.

* gnu/packages/maths.scm (units): Update to 2.12.

* guix/scripts/challenge.scm, tests/challenge.scm: New files.
* Makefile.am (MODULES): Add the former.
  (SCM_TESTS): Add the latter.
* doc.am (SUBCOMMANDS): Add 'challenge'.
* doc/guix.texi (Substitutes): Add xref to 'guix challenge'.
  (Invoking guix challenge): New node.
* doc/contributing.texi (Submitting Patches): Add note about using 'guix
  challenge'.
* po/guix/POTFILES.in: Add guix/scripts/challenge.scm.

* guix/scripts/substitute.scm: Export <narinfo> accessors.
  (narinfo-hash->sha256): New procedure.
  (cache-narinfo!): Ignore EACCES exceptions.

* guix/scripts/archive.scm (show-help, %options): Add --extract.
  (guix-archive): Honor it.
* tests/guix-archive.sh: Test it.
* doc/guix.texi (Invoking guix archive): Document it.

* gnu/packages/freedesktop.scm (elogind)[inputs]: Add DMD.

* gnu/packages/gnunet.scm (gnurl): Update to 7.44.0.

* gnu/packages/ebook.scm (calibre): Update to 2.41.0.

* gnu/packages/video.scm (youtube-dl): Update to 2015.10.16.

* gnu/packages/bioinformatics.scm (ngs-sdk): Correct typo.

* gnu/packages/bioinformatics.scm (ngs-sdk)[supported-systems]: Keep only x86
  based systems.

* gnu/packages/games.scm (chess): Update to 6.2.2.

* gnu/packages/music.scm (non-sequencer)[arguments]: Add "--disable-sse"
  flag when not building on x86_64.

* gnu/packages/engineering.scm (fastcap): Do it.

* gnu/packages/engineering.scm (fastcap): Adapt documentation generation to
  change in TeXLive 2015.

* emacs/guix-devel.el (guix-devel-keywords): New constant.
  (guix-devel-font-lock-keywords): Use it.

* doc/emacs.texi (Emacs Popup Interface): Document "View graph" action.

Suggested by Ludovic Courtès <ludo@gnu.org>.

* emacs/guix-external.el (guix-png-file-name): Change prefix of a file
  name to "guix-emacs-graph-" to avoid possible conflicts.

* guix/gnu-maintenance.scm (official-gnu-packages): Close the port
  returned by FETCH.

This speeds up operations like 'guix lint -c gnu-description'.

* guix/gnu-maintenance.scm (official-gnu-packages): Add 'fetch'
  parameter and honor it.  Default to 'http-fetch/cached'.

* guix/utils.scm (cache-directory): New procedure.
* guix/http-client.scm (%http-cache-ttl): New variable.
  (http-fetch/cached): New procedure.

Reported by anthk_ on #guix in Sept. 2015.

* gnu/system/install.scm (self-contained-tarball): Use --mtime=@1
  instead of --mtime=@0.

* gnu/packages/code.scm (complexity): Update to 1.3.

Reported by David Thompson <dthompson2@worcester.edu>
at <https://lists.gnu.org/archive/html/guix-devel/2015-10/msg00284.html>.

* gnu/build/file-systems.scm (mount-file-system): When SOURCE matches
  'regular-file?', do not create MOUNT-POINT if it already exists.  This
  fixes a bug whereby we would be truncating MOUNT-POINT if it already
  existed.

Fixes <http://bugs.gnu.org/21694>.

* guix/build/syscalls.scm (clone): Change 'syscall' parameter types to
  LONG, UNSIGNED-LONG, or '*; make sure it has 6 parameters.  Adjust
  caller accordingly.