Merge branch 'master' into core-updates

sync-with-upstream: Generate 'nix/AUTHORS'.

* nix/sync-with-upstream: Use 'git shortlog' to generate nix/AUTHORS.

daemon: Rename '--disable-store-optimization' to '--disable-deduplication'.

* nix/nix-daemon/guix-daemon.cc (GUIX_OPT_DISABLE_STORE_OPTIMIZATION):
  Rename to...
  (GUIX_OPT_DISABLE_DEDUPLICATION): ... this.  Adjust user accordingly.
  (options): Add "disable-deduplication".  Make
  "disable-store-optimization" a hidden alias.
* doc/guix.texi (Invoking guix-daemon): Adjust to new option name.  Add
  index entry.  Improve description.

daemon: Really enable automatic deduplication by default.

* nix/nix-daemon/guix-daemon.cc (main): Set 'autoStoreOptimise' to
  true.  Add 'printMsg' call.
* tests/derivations.scm ("identical files are deduplicated"): New test.

Merge branch 'master' into core-updates

guix-register: By default, attempt to deduplicate registered items.

* nix/guix-register/guix-register.cc (GUIX_OPT_DEDUPLICATE): New macro.
  (options): Add --no-deduplication.
  (deduplication): New variable.
  (parse_opt): Handle GUIX_OPT_DEDUPLICATE.
  (register_validity): Add 'optimize' parameter and honor it.
  (main): Move 'store' instanatiation after 'settings.nixStore'
  assignment.
* tests/guix-register.sh: Add test for deduplication.
* guix/nar.scm (finalize-store-file): Update comment above
  'register-path' call.

guix-register: Add '--state-directory' parameter.

* nix/guix-register/guix-register.cc (GUIX_OPT_STATE_DIRECTORY): New
  macro.
  (parse_opt): Honor it.
* tests/guix-register.sh: Add test with '--state-directory'.
* guix/store.scm (register-path): Add #:state-directory parameter.

guix-register: Add explicit libgcrypt initialization.

* nix/guix-register/guix-register.cc (main): Add calls to
  'gcry_check_version' and 'gcry_control', to appease libgcrypt.

Merge branch 'master' into core-updates

list-runtime-roots: Don't display a backtrace on 2.0.5 when lsof is lacking.

* nix/scripts/list-runtime-roots.in (lsof-roots): Fix typo in 'catch'
  tag.  Add 'parent' variable.  Wrap 'open-pipe*' call in 'catch'.
  Reported by Andreas Enge <andreas@enge.fr>.

daemon: Don't abort when $PATH is undefined.

* nix/nix-daemon/guix-daemon.cc (main): Check whether getenv ("PATH")
  returns NULL before blindly initializing 'search_path'.  Before that
  'guix-daemon' would abort when run in an environment where 'PATH' is
  undefined.

daemon: Clear $NIX_SUBSTITUTERS when passed '--no-substitutes'.

* nix/nix-daemon/guix-daemon.cc (main): When --no-substitutes is used,
  clear NIX_SUBSTITUTERS.  Before that, and after
  89faa5c75cb3a419c6d02c51f56955275b7ae351, '--no-substitutes' would
  lead to attempts to use 'download-using-manifests.pl', which in
  practice would gracelessly fail.

daemon: Change some options via 'settings.set'.

* nix/nix-daemon/guix-daemon.cc (parse_opt): Use 'settings.set' instead
  of direct field access for 'buildCores', 'maxBuildJobs', and
  'useSubstitutes'.
  (main): Call 'settings.update' after 'argp_parse'.

Merge branch 'master' into core-updates

daemon: Really override the substituters setting.

Reported by Andreas Enge <andreas@enge.fr>:
<https://lists.gnu.org/archive/html/guix-devel/2014-03/msg00211.html>.

* nix/nix-daemon/guix-daemon.cc (main): Set the 'NIX_SUBSTITUTERS'
  env. var.  Leave 'settings.substituters' unchanged.

Merge branch 'master' into core-updates

Conflicts:
	gnu-system.am

daemon: Add '--gc-keep-outputs' and '--gc-keep-derivations'.

* nix/nix-daemon/guix-daemon.cc (GUIX_OPT_GC_KEEP_OUTPUTS,
  GUIX_OPT_GC_KEEP_DERIVATIONS): New macros.
  (options): Add 'gc-keep-outputs' and 'gc-keep-derivations'.
  (string_to_bool): New function.
  (parse_opt): Honor GUIX_OPT_GC_KEEP_DERIVATIONS and
  GUIX_OPT_GC_KEEP_OUTPUTS.
* doc/guix.texi (Invoking guix-daemon): Document --gc-keep-outputs and
  --gc-keep-derivations.

Merge branch 'master' into core-updates

Add 'guix offload' as a daemon build hook.

* nix/nix-daemon/guix-daemon.cc (GUIX_OPT_NO_BUILD_HOOK): New macro.
  (options): Add '--no-build-hook'.
  (parse_opt): Handle it.
  (main)[HAVE_DAEMON_OFFLOAD_HOOK]: Set 'useBuildHook' by default.
  Set $NIX_BUILD_HOOK to our offload hook unless otherwise specified.
  [!HAVE_DAEMON_OFFLOAD_HOOK]: Clear 'useBuildHook'.
* pre-inst-env.in: Set and export NIX_BUILD_HOOK.
* nix/scripts/offload.in, guix/scripts/offload.scm: New files.
* guix/ui.scm (show-guix-help)[internal?]: Add "offload".
* config-daemon.ac: Call 'GUIX_CHECK_UNBUFFERED_CBIP'.
  Instantiate 'nix/scripts/offload'.  Set 'BUILD_DAEMON_OFFLOAD'
  conditional, and optionally define 'HAVE_DEAMON_OFFLOAD_HOOK' cpp
  macro.
* daemon.am (nodist_pkglibexec_SCRIPTS)[BUILD_DAEMON_OFFLOAD]: Add it.
* Makefile.am (MODULES)[BUILD_DAEMON_OFFLOAD]: Add
  'guix/scripts/offload.scm'.
  (EXTRA_DIST)[!BUILD_DAEMON_OFFLOAD]: Likewise.
* m4/guix.m4 (GUIX_CHECK_UNBUFFERED_CBIP): New macro.
* doc/guix.texi (Setting Up the Daemon): Move most of the body to...
  (Build Environment Setup): ... this.  New subsection.
  (Daemon Offload Setup): New subsection.

guix-register: Support registration in the current store, without '--prefix'.

* nix/guix-register/guix-register.cc (register_validity): Leave
  'info.path' unmodified when PREFIX is empty.
  (main): Call 'settings.processEnvironment' early on.
  Leave 'settings.nixStore' unmodified when PREFIX is empty.