* 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.

* gnu/packages/linux.scm (numactl): New variable.

* gnu/packages/mpi.scm (openmpi)[origin]: Fix typo.

* gnu/packages/algebra.scm (fftw)[inputs,arguments]: Add OpenMPI.

* gnu/packages/algebra.scm (fftw): Upgrade to 3.3.4.

* gnu/services/base.scm (root-file-system-service,
  user-processes-service): New procedures.
  (mingetty-service, nscd-service, syslog-service, guix-service): Add
  requirement on 'user-processes'.
  (%base-services): Add (user-processes-service)
  and (root-file-system-service).
* gnu/services/xorg.scm (slim-service): Add requirement on
  'user-processes'.

* guix/build/linux-initrd.scm (switch-root): Simplify /dev/console
  code.  This fixes a bug where we would leak the IN and OUT file
  descriptors.

* doc/guix.texi (G-Expressions): Mention Oleg's work on "staging" in
  footnote.

* guix/build/git.scm (git-fetch): Add 'setenv' call.

* gnu/packages/mpi.scm (openmpi)[synopsis,description]: Remove mention
  of "open source".

* gnu/packages/maths.scm (petsc-openmpi): New variable.
  (petsc-complex-openmpi): New variable.

* gnu/packages/maths.scm (petsc)[arguments]: Scrub some
  config-generated header files before build.  Only remove files if
  they exist.

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

* .gitmodules: Use https, not http.  Reported by
  Pjotr Prins <pjotr.public12@thebird.nl>.

* guix/build/linux-initrd.scm (mount-root-file-system): Populate
  /root/etc/mtab.
  (mount-file-system): Update ROOT/etc/mtab.

* guix/build/gnome.scm: Remove.
* Makefile.am (MODULES): Update accordingly.

* gnu/packages/glib.scm (glib): Add 'native-search-paths' and
  'search-paths' fields.
* gnu/packages/gnome.scm (libpeas): Remove 'arguments' field.
  (librsvg)[arguments]: Remove #:modules and #:imported-modules.
  Remove settings of INTROSPECTION_SCANNER_ARGS and
  INTROSPECTION_COMPILER_ARGS in makefiles.
* gnu/packages/gtk.scm (gtk+): Likewise.

* gnu/packages/gtk.scm (atk, pango, gdk-pixbuf, gtk+): Move
  gobject-introspection to 'native-inputs' since it's only used at build
  time.
* gnu/packages/gnome.scm (libpeas): Move pkg-config,
  gobject-introspection, and intltool to 'native-inputs'.

* gnu/packages/gnome.scm (librsvg): New variable.

* guix/build/linux-initrd.scm (switch-root): Delete file from the old
  root.  Chdir to / after 'chroot' call.  Re-open file descriptors 0, 1,
  and 2.
  (boot-system): Move 'loading' message after the 'switch-root' call.
* gnu/system.scm (operating-system-boot-script): Add loop that closes
  file descriptor before calling 'execl'.

* gnu/packages/gnupg.scm (pius): Use Python 2.

* gnu/packages/make-bootstrap.scm: Export '%guile-static-stripped'.  The
  problem was hidden because of <http://bugs.gnu.org/17418>.

* gnu/packages/linux.scm (e2fsprogs)[native-inputs]: Add TEXINFO.

* gnu/packages/linux.scm (e2fsprogs/static): Remove.
  (e2fsck/static): Use (static-package e2fsprogs) instead.

* gnu/packages/gdb.scm (gdb): Upgrade to 7.7.1.

* gnu/packages/gdb.scm (gdb)[inputs]: Add LIBXML2.

* gnu/packages/gnome.scm (libgsf): New variable.

* gnu/packages/gnome.scm (libcroco): New variable.

* gnu/packages/python.scm (python2-pybugz)[source]: Add 'patches'
  field.
* gnu/packages/patches/pybugz-encode-error.patch,
  gnu/packages/patches/pybugz-stty.patch: New files.
* gnu-system.am (dist_patch_DATA): Add them.

* guix/gnu-maintenance.scm (gnu-package?): Only call 'mirror-type' when
  URL is a string.

* guix/build/linux-initrd.scm (move-essential-file-systems,
  switch-root): New procedures.
  (MS_MOVE): New variable.
  (boot-system): Remove 'mount-essential-file-systems' call for ROOT.
  Use 'switch-root' instead of chdir + chroot.

* gnu/services/networking.scm (static-networking-service): Use
  $inetutils/bin/ifconfig, not $inetutils/sbin/ifconfig.