* guix/scripts/system.scm (show-help): Document 'build' action.
  (guix-system): Honor 'build' action.
* doc/guix.texi (Invoking guix system): Add 'build' action.

* gnu/packages/libevent.scm (libuv): New variable.

* guix/scripts/authenticate.scm (%default-port-conversion-strategy): New
  variable.  Reported by Andreas Enge <andreas@enge.fr>.

* 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>.

* guix/build/vm.scm (install-grub, evaluate-populate-directive,
  reset-timestamps, register-closure): Move to...
* guix/build/install.scm: ... here.  New file.
* Makefile.am (MODULES): Add it.
* gnu/system/vm.scm (expression->derivation-in-linux-vm): Add (guix
  build install) to #:modules.

* gnu/system/vm.scm (qemu-image): Rename #:inputs-to-copy to #:inputs,
  and #:initialize-store? to #:register-closures?.  Add #:copy-inputs?.
  Adjust build gexp accordingly.
  (system-qemu-image): Remove #:initialize-store? argument and add
  #:copy-inputs?.
  (system-qemu-image/shared-store): Add #:inputs, #:register-closures?,
  and #:copy-inputs? arguments.
* guix/build/vm.scm (register-closure): New procedure.
  (MS_BIND): New variable.
  (initialize-hard-disk): Rename #:initialize-store? to
  #:register-closures?, #:closures-to-copy to #:closures, and add
  #:copy-closures?.
  Add 'target-directory' and 'target-store' variables.
  Call 'populate-store' only when COPY-CLOSURES?.
  Bind-mount the store to TARGET-STORE when REGISTER-CLOSURES? and not
  COPY-CLOSURES?.  Add call to 'register-closure'.

* build-aux/hydra/demo-os.scm (file-systems): Comment out
  %FUSE-CONTROL-FILE-SYSTEM, since fuse.ko is missing by default in the
  freestanding VM image.

* gnu/system.scm (%fuse-control-file-system,
  %binary-format-file-system): New variables.
* build-aux/hydra/demo-os.scm (file-systems): New field.

* gnu/system/vm.scm (virtualized-operating-system): Instead of
  completely overriding 'file-systems', use 'remove' to filter out some
  of those declared in OS.
  (system-qemu-image): Likewise.

* gnu/packages/xorg.scm (xterm): Upgrade to 304.  Switch to a
  version-specific URL.

* guix/build/activation.scm (add-user): Don't pass '--create-home' when
  HOME already exists.

* guix/build/linux-initrd.scm (make-essential-device-nodes): Make
  /dev/ttyS0.

* guix/build/linux-initrd.scm (pidof): New procedure.
  (mount-root-file-system)[mark-as-not-killable]: New procedure.
  Use it for unionfs when VOLATILE-ROOT?.
* gnu/services/base.scm (%do-not-kill-file): New variable.
  (user-processes-service)[stop]: Honor it.

* guix/build/syscalls.scm (kernel?, processes): New procedures.

* gnu/packages/xorg.scm (libsm): Propagate input libice.

* gnu/packages/qt.scm (qt-4): Upgrade to 4.8.6.

* gnu/packages/qt.scm (qt-4): Add input qt-4.

* gnu/system/vm.scm (system-qemu-image/shared-store-script): Add
  '-serial stdio'.

* gnu/system.scm (default-skeletons, skeleton-directory): Move to...
* gnu/system/shadow.scm: ... here.

* doc/guix.texi (Installing Debugging Files): Add @cindex.  Remove
  unneeded '-i' in example.  Mention source code an 'directory'.  Link
  to "Build Systems" instead of "Defining Packages".

* gnu/system.scm (default-skeletons): Add .gdbinit.

* gnu/packages/mpi.scm (hwloc): Propagate numactl.
  (openmpi)[inputs]: Add hwloc.
  [native-inputs]: Add pkg-config.
  [argument]: Add hwloc configure flags.

* gnu/packages/gimp.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.

* gnu/system.scm (<operating-system>)[skeletons]: New field.
  (default-skeletons, skeleton-directory): New procedures.
  (etc-directory): Add #:skeletons parameter.  Call
  'skeleton-directory', and produce the 'skel' sub-directory.
  (operating-system-etc-directory): Pass #:skeletons to
  'etc-directory'.

* doc/guix.texi (Invoking guix package): Add LGPLv3 example.

* gnu/packages/patches/perl-tk-x11-discover.patch: New patch.
* gnu-system.am [dist_patch_DATA]: Add it.
* gnu/packages/tcl.scm (perl-tk)[origin]: Use it.

* gnu/services/base.scm (guix-build-accounts): Remove #:gid parameter;
  add #:group.  Remove 'password' and 'gid' fields in 'user-account'
  form, and add 'group'.
  (guix-service): Remove #:build-user-gid parameter.  Remove 'id' field
  in 'user-group' form.
* gnu/system.scm (etc-directory): Remove #:groups and #:accounts.  No
  longer produce files "passwd", "shadow", and "group".  Adjust caller
  accordingly.
  (%root-account): New variable.
  (operating-system-accounts): Add 'users' variable.  Add %ROOT-ACCOUNT
  only of 'operating-system-users' doesn't already contain a root
  account.
  (user-group->gexp, user-account->gexp): New procedures.
  (operating-system-boot-script): Add calls to 'setenv' and
  'activate-users+groups' in gexp.
* gnu/system/linux.scm (base-pam-services): Add PAM services for
  "user{add,del,mode}" and "group{add,del,mod}".
* gnu/system/shadow.scm (<user-account>)[gid]: Rename to...
  [group]: ... this.
  [supplementary-groups]: New field.
  [uid, password]: Default to #f.
  (<user-group>)[id]: Default to #f.
  (group-file, passwd-file): Remove.
* gnu/system/vm.scm (operating-system-default-contents)[user-directories]:
  Remove.  Add "/home" to the directives.
* guix/build/activation.scm (add-group, add-user,
  activate-users+groups): New procedures.

* gnu/services/xorg.scm (slim-service): Add missing whitespace in
  XINITRC invocation.

* gnu/packages/maths.scm (pspp): Update to 0.8.3.

* HACKING (Commit Access): Mention upgrades that trigger a lot rebuilds.

* doc/guix.texi (Perl modules): New section explaining the naming of perl
    modules.

* gnu/system/vm.scm (operating-system-build-gid): Adjust to new return
  type of 'operating-system-services' introduced in 217a5b85.

* gnu/services/base.scm (file-system-service): New procedure.
  (user-processes-service): Add 'requirements' parameter.
* gnu/services/dmd.scm (dmd-configuration-file): Use (guix build
  linux-initrd).
* guix/build/linux-initrd.scm (guix): Export 'check-file-system'.
* gnu/system.scm (file-union): New procedure.
  (essential-services): Use it.  Add that to the returned list.

* gnu/services/dmd.scm (dmd-configuration-file): Add derivations for
  the (guix build syscalls) module, and add that to the load path of
  dmd.conf.
* gnu/services/base.scm (root-file-system-service): Rewrite using the
  'sync' and 'mount' procedures.

* guix/build/syscalls.scm, tests/syscalls.scm: New files.
* Makefile.am (MODULES): Add guix/build/syscalls.scm.
  (SCM_TESTS): Add tests/syscalls.scm.
* guix/utils.scm (%libc-errno-pointer, errno): Remove; take from (guix
  build syscalls).

* guix/build/linux-initrd.scm (mount-file-system): Open /etc/mtab in
  append mode.

* gnu/services/base.scm (%base-services): Remove calls to
  'host-name-service', 'user-processes-service', and
  'root-file-system-service'.
* gnu/system.scm (<operating-system>)[operating-system-services]: Rename
  to...
  [operating-system-user-services]: ... this.
  (essential-services, operating-system-services): New procedures.
  (operating-system-accounts, operating-system-etc-directory,
  operating-system-boot-script, operating-system-derivation): Adjust to
  new 'operating-system-services' return type.

* gnu/packages/algebra.scm (fftw)[inputs,arguments]: Remove OpenMPI.
  (fftw-openmpi): New variable.

* gnu/packages/mpi.scm (hwloc): New variable.
  (openmpi): Add TODO comment.

* gnu/packages/pciutils.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.