* guix/scripts/package.scm (matching-generations): Add
  'duration-relation' keyword parameter.
  (guix-package)[process-action](delete-generations): Pass
  #:duration-relation >.
* tests/guix-package.sh: Add test.
* doc/guix.texi (Invoking guix package): Clarify the meaning of
  durations for '--list-durations' and '--delete-durations'.

* tests/guix-package.sh: Add missing "-p" option.

* gnu/system/vm.scm (system-qemu-image): Add procps, psmisc, and Zile to
  the default profile.  Increase the image size to 550 MiB.

* gnu/system/dmd.scm (static-networking-service)[start]: Sleep before
  running 'route', to leave time for the interface to come up.
  [stop]: Run "route del -net default".

* gnu/system/vm.scm (qemu-image): Change the store's mode to #o1775.
  Support 'populate' clauses that specify a UID and GID.
  (system-qemu-image): Make sure /nix/store has owner 'root' and group
  'guixbuild'.  Set the right owner for /home/guest.  Create
  /var/nix/profiles/per-user/{root,guest}.

* gnu/packages/linux-initrd.scm (gnu-system-initrd): Make sure /root/tmp
  exists; mount it as a tmpfs.

* gnu/system/shadow.scm (guix-build-accounts): New procedure.
* gnu/system/vm.scm (system-qemu-image): Use it.  Add the "guixbuild"
  group.
* gnu/system/dmd.scm (guix-service): Add 'builder-group' parameter.
  Pass 'guix-daemon' the '--build-users-group' option.

* gnu/system/vm.scm (system-qemu-image): Link
  /etc/{services,protocols,rpc}.  Add net-base as an input.

* scripts/guix.in: Change '-s' to '--no-auto-compile'.  This avoids
  annoying messages about auto-compilation, and avoids permission denied
  issues when running without write access in the usual places.

* gnu/system/vm.scm (system-qemu-image): Add a "guest" user and a
  "users" user group.  Make /home/guest.  Add /etc/group.  Update
  /etc/issue to mention it.

* gnu/system/shadow.scm (<user-group>): New record type.
  (group-file): New procedure.
* gnu/system/vm.scm (system-qemu-image): Use it.

* gnu/system/shadow.scm (<user-account>): New record type.
  (passwd-file): Use it.
* gnu/system/vm.scm (system-qemu-image): Adjust accordingly.

* gnu/packages/system.scm (net-base): New variable.

* guix/build-system/trivial.scm (trivial-build): When SOURCE is true,
  add it to INPUTS.
  (trivial-cross-build): Likewise.
* tests/packages.scm ("trivial with source"): New test.

* gnu/system/dmd.scm (static-networking-service): Add #:gateway
  parameter and honor it.
* gnu/system/vm.scm (system-qemu-image): Pass #:gateway to
  'static-networking-service'.

* gnu/packages/linux.scm (net-tools): New variable.

* gnu/packages/system.scm (dmd): Use the alpha.gnu.org URL.

* gnu/packages/gtk.scm (harfbuzz): Update to 0.9.21.

* gnu/packages/cdrom.scm (dvdisaster): New variable.

* guix/scripts/package.scm (switch-to-previous-generation): New function.
  (roll-back): Use the new function instead of 'switch-link'.
  (show-help): Add '--delete-generations'.
  (%options): Likewise.
  (guix-package)[process-actions]: Add 'current-generation-number',
  'display-and-delete', and 'delete-generation'.  Add support for
  '--delete-generations', and reindent the code.
* tests/guix-package.sh: Test '--delete-generations'.
* doc/guix.texi (Invoking guix-package): Document '--delete-generations'.

* guix/scripts/package.scm (link-to-empty-profile): New function.
  (roll-back): Use it.

* guix/scripts/package.scm (guix-package)[process-query]: Exit with 0
  when there are no generations containing packages or no profiles.

* gnu/packages/xorg.scm (xf86-input-joystick): Fix installation path.

* gnu/packages/xorg.scm (xf86-input-vmmouse): Fix installation path.

* gnu/packages/xorg.scm (xf86-input-synaptics): Fix installation paths.

* gnu/packages/zile.scm (zile): Add 'patch-/bin/sh' phase.  Move Perl
  and help2man to 'native-inputs'.

* gnu/system/dmd.scm (nscd-service): New procedure.
* gnu/system/vm.scm (system-qemu-image): Use it.  Make /var/run/nscd.

* guix/packages.scm (package-output): Make the 'output' parameter
  optional.

* gnu/system/vm.scm (system-qemu-image): Use
  'static-networking-service'.  Add /etc/resolv.conf.  Add Inetutils to
  the profile.
* gnu/system/dmd.scm (static-networking-service): New procedure.

* gnu/system/vm.scm (system-qemu-image): Register PROFILE as a GC root.

* gnu/system/dmd.scm (host-name-service): New procedure.
  (mingetty-service): Require the 'host-name' service.
* gnu/system/vm.scm (system-qemu-image): Add the 'host-name' service.
  Set PS1 in /etc/bashrc to something sensible.

* gnu/system/vm.scm (system-qemu-image): Build a 'motd' and an 'issue'
  file.  Pass 'unix-pam-service' that motd.  Have /etc/issue point to
  the 'issue' file.

* gnu/system/vm.scm (qemu-image): Change 'populate' parameter to be a
  list of directives.
  (system-qemu-image): Adjust accordingly.

* gnu/system/vm.scm (system-qemu-image): Add more ttys.

* gnu/system/vm.scm (system-qemu-image): Change GRUB label.

* gnu/system/vm.scm (qemu-image): Add Guix as an input when
  INITIALIZE-STORE?.
  (union): New procedure.
  (system-qemu-image): Use it.  Build /etc/profile.  Pass PROFILE among
  #:inputs-to-copy instead of listing all the individual profiles.
  Remove explicit 'build-derivations' call.

* gnu/system/vm.scm (expression->derivation-in-linux-vm)[input-alist]:
  Add case for derivation? objects.
  Same for #:inputs values.
  (qemu-image)[input->name+derivation]: Likewise.

* guix/scripts/package.scm (guix-package)[process-query]: Show that a
  generation is the current one if the profile points to it.
* tests/guix-package.sh: Test it.