<section xmlns="http://docbook.org/ns/docbook"
         xmlns:xlink="http://www.w3.org/1999/xlink"
         xmlns:xi="http://www.w3.org/2001/XInclude"
         version="5.0"
         xml:id="sec-release-15.09">

<title>Release 15.09 (“Dingo”, 2015/09/30)</title>

<para>In addition to numerous new and upgraded packages, this release
has the following highlights:</para>

<itemizedlist>

  <listitem>
    <para>Gnome has been upgraded to 3.16.
    </para>
  </listitem>

  <listitem>
    <para>Xfce has been upgraded to 4.12.
    </para>
  </listitem>

  <listitem>
    <para>KDE 5 has been upgraded to KDE Frameworks 5.10,
      Plasma 5.3.2 and Applications 15.04.3.
      KDE 4 has been updated to kdelibs-4.14.10.
    </para>
  </listitem>

  <listitem>
    <para>E19 has been upgraded to 0.16.8.15.
    </para>
  </listitem>

  <listitem>
    <para>The <link xlink:href="http://haskell.org/">Haskell</link>
    packages infrastructure has been re-designed from the ground up
    (&quot;Haskell NG&quot;). NixOS now distributes the latest version
    of every single package registered on <link
    xlink:href="http://hackage.haskell.org/">Hackage</link> -- well in
    excess of 8,000 Haskell packages. Detailed instructions on how to
    use that infrastructure can be found in the <link
    xlink:href="http://nixos.org/nixpkgs/manual/#users-guide-to-the-haskell-infrastructure">User's
    Guide to the Haskell Infrastructure</link>. Users migrating from an
    earlier release may find helpful information below, in the list of
    backwards-incompatible changes. Furthermore, we distribute 51(!)
    additional Haskell package sets that provide every single <link
    xlink:href="http://www.stackage.org/">LTS Haskell</link> release
    since version 0.0 as well as the most recent <link
    xlink:href="http://www.stackage.org/">Stackage Nightly</link>
    snapshot. The announcement <link
    xlink:href="http://lists.science.uu.nl/pipermail/nix-dev/2015-September/018138.html">&quot;Full
    Stackage Support in Nixpkgs&quot;</link> gives additional
    details.</para>
  </listitem>

  <listitem>
    <para>Nix has been updated to version 1.10, which among other
    improvements enables cryptographic signatures on binary caches for
    improved security.</para>
  </listitem>

  <listitem>
    <para>You can now keep your NixOS system up to date automatically
    by setting

<programlisting>
system.autoUpgrade.enable = true;
</programlisting>

    This will cause the system to periodically check for updates in
    your current channel and run <command>nixos-rebuild</command>.</para>
  </listitem>

  <listitem>
    <para>This release is based on Glibc 2.21, GCC 4.9 and Linux
    3.18.</para>
  </listitem>

</itemizedlist>


  <para>Following new services were added since the last release:

  <itemizedlist>
    <listitem><para><literal>services/mail/exim.nix</literal></para></listitem>
    <listitem><para><literal>services/misc/apache-kafka.nix</literal></para></listitem>
    <listitem><para><literal>services/misc/canto-daemon.nix</literal></para></listitem>
    <listitem><para><literal>services/misc/confd.nix</literal></para></listitem>
    <listitem><para><literal>services/misc/devmon.nix</literal></para></listitem>
    <listitem><para><literal>services/misc/gitit.nix</literal></para></listitem>
    <listitem><para><literal>services/misc/ihaskell.nix</literal></para></listitem>
    <listitem><para><literal>services/misc/mbpfan.nix</literal></para></listitem>
    <listitem><para><literal>services/misc/mediatomb.nix</literal></para></listitem>
    <listitem><para><literal>services/misc/mwlib.nix</literal></para></listitem>
    <listitem><para><literal>services/misc/parsoid.nix</literal></para></listitem>
    <listitem><para><literal>services/misc/plex.nix</literal></para></listitem>
    <listitem><para><literal>services/misc/ripple-rest.nix</literal></para></listitem>
    <listitem><para><literal>services/misc/ripple-data-api.nix</literal></para></listitem>
    <listitem><para><literal>services/misc/subsonic.nix</literal></para></listitem>
    <listitem><para><literal>services/misc/sundtek.nix</literal></para></listitem>
    <listitem><para><literal>services/monitoring/cadvisor.nix</literal></para></listitem>
    <listitem><para><literal>services/monitoring/das_watchdog.nix</literal></para></listitem>
    <listitem><para><literal>services/monitoring/grafana.nix</literal></para></listitem>
    <listitem><para><literal>services/monitoring/riemann-tools.nix</literal></para></listitem>
    <listitem><para><literal>services/monitoring/teamviewer.nix</literal></para></listitem>
    <listitem><para><literal>services/network-filesystems/u9fs.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/aiccu.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/asterisk.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/bird.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/charybdis.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/docker-registry-server.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/fan.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/firefox/sync-server.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/gateone.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/heyefi.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/i2p.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/lambdabot.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/mstpd.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/nix-serve.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/nylon.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/racoon.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/skydns.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/shout.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/softether.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/sslh.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/tinc.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/tlsdated.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/tox-bootstrapd.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/tvheadend.nix</literal></para></listitem>
    <listitem><para><literal>services/networking/zerotierone.nix</literal></para></listitem>
    <listitem><para><literal>services/scheduling/marathon.nix</literal></para></listitem>
    <listitem><para><literal>services/security/fprintd.nix</literal></para></listitem>
    <listitem><para><literal>services/security/hologram.nix</literal></para></listitem>
    <listitem><para><literal>services/security/munge.nix</literal></para></listitem>
    <listitem><para><literal>services/system/cloud-init.nix</literal></para></listitem>
    <listitem><para><literal>services/web-servers/shellinabox.nix</literal></para></listitem>
    <listitem><para><literal>services/web-servers/uwsgi.nix</literal></para></listitem>
    <listitem><para><literal>services/x11/unclutter.nix</literal></para></listitem>
    <listitem><para><literal>services/x11/display-managers/sddm.nix</literal></para></listitem>
    <listitem><para><literal>system/boot/coredump.nix</literal></para></listitem>
    <listitem><para><literal>system/boot/loader/loader.nix</literal></para></listitem>
    <listitem><para><literal>system/boot/loader/generic-extlinux-compatible</literal></para></listitem>
    <listitem><para><literal>system/boot/networkd.nix</literal></para></listitem>
    <listitem><para><literal>system/boot/resolved.nix</literal></para></listitem>
    <listitem><para><literal>system/boot/timesyncd.nix</literal></para></listitem>
    <listitem><para><literal>tasks/filesystems/exfat.nix</literal></para></listitem>
    <listitem><para><literal>tasks/filesystems/ntfs.nix</literal></para></listitem>
    <listitem><para><literal>tasks/filesystems/vboxsf.nix</literal></para></listitem>
    <listitem><para><literal>virtualisation/virtualbox-host.nix</literal></para></listitem>
    <listitem><para><literal>virtualisation/vmware-guest.nix</literal></para></listitem>
    <listitem><para><literal>virtualisation/xen-dom0.nix</literal></para></listitem>
  </itemizedlist>
  </para>


<para>When upgrading from a previous release, please be aware of the
following incompatible changes:

<itemizedlist>

<listitem><para><command>sshd</command> no longer supports DSA and ECDSA
host keys by default. If you have existing systems with such host keys
and want to continue to use them, please set

<programlisting>
system.stateVersion = "14.12";
</programlisting>

The new option <option>system.stateVersion</option> ensures that
certain configuration changes that could break existing systems (such
as the <command>sshd</command> host key setting) will maintain
compatibility with the specified NixOS release. NixOps sets the state
version of existing deployments automatically.</para></listitem>

<listitem><para><command>cron</command> is no longer enabled by
default, unless you have a non-empty
<option>services.cron.systemCronJobs</option>. To force
<command>cron</command> to be enabled, set
<option>services.cron.enable = true</option>.</para></listitem>

<listitem><para>Nix now requires binary caches to be cryptographically
signed. If you have unsigned binary caches that you want to continue
to use, you should set <option>nix.requireSignedBinaryCaches =
false</option>.</para></listitem>

<listitem><para>Steam now doesn't need root rights to work. Instead of using
<literal>*-steam-chrootenv</literal>, you should now just run <literal>steam</literal>.
<literal>steamChrootEnv</literal> package was renamed to <literal>steam</literal>,
and old <literal>steam</literal> package -- to <literal>steamOriginal</literal>.
</para></listitem>

<listitem><para>CMPlayer has been renamed to bomi upstream. Package
<literal>cmplayer</literal> was accordingly renamed to
<literal>bomi</literal> </para></listitem>

<listitem><para>Atom Shell has been renamed to Electron upstream.  Package <literal>atom-shell</literal>
was accordingly renamed to <literal>electron</literal>
</para></listitem>

<listitem><para>Elm is not released on Hackage anymore. You should now use <literal>elmPackages.elm</literal>
which contains the latest Elm platform.</para></listitem>

<listitem>
  <para>The CUPS printing service has been updated to version
  <literal>2.0.2</literal>.  Furthermore its systemd service has been
  renamed to <literal>cups.service</literal>.</para>

  <para>Local printers are no longer shared or advertised by
  default. This behavior can be changed by enabling
  <option>services.printing.defaultShared</option> or
  <option>services.printing.browsing</option> respectively.</para>
</listitem>

<listitem>
  <para>
    The VirtualBox host and guest options have been named more
    consistently. They can now found in
    <option>virtualisation.virtualbox.host.*</option> instead of
    <option>services.virtualboxHost.*</option> and
    <option>virtualisation.virtualbox.guest.*</option> instead of
    <option>services.virtualboxGuest.*</option>.
  </para>

  <para>
    Also, there now is support for the <literal>vboxsf</literal> file
    system using the <option>fileSystems</option> configuration
    attribute. An example of how this can be used in a configuration:

<programlisting>
fileSystems."/shiny" = {
  device = "myshinysharedfolder";
  fsType = "vboxsf";
};
</programlisting>

  </para>
</listitem>

<listitem>
  <para>
    &quot;<literal>nix-env -qa</literal>&quot; no longer discovers
    Haskell packages by name. The only packages visible in the global
    scope are <literal>ghc</literal>, <literal>cabal-install</literal>,
    and <literal>stack</literal>, but all other packages are hidden. The
    reason for this inconvenience is the sheer size of the Haskell
    package set. Name-based lookups are expensive, and most
    <literal>nix-env -qa</literal> operations would become much slower
    if we'd add the entire Hackage database into the top level attribute
    set. Instead, the list of Haskell packages can be displayed by
    running:
  </para>
  <programlisting>
nix-env -f &quot;&lt;nixpkgs&gt;&quot; -qaP -A haskellPackages
</programlisting>
  <para>
    Executable programs written in Haskell can be installed with:
  </para>
  <programlisting>
nix-env -f &quot;&lt;nixpkgs&gt;&quot; -iA haskellPackages.pandoc
</programlisting>
  <para>
    Installing Haskell <emphasis>libraries</emphasis> this way, however, is no
    longer supported. See the next item for more details.
  </para>
</listitem>

<listitem>
  <para>
    Previous versions of NixOS came with a feature called
    <literal>ghc-wrapper</literal>, a small script that allowed GHC to
    transparently pick up on libraries installed in the user's profile. This
    feature has been deprecated; <literal>ghc-wrapper</literal> was removed
    from the distribution. The proper way to register Haskell libraries with
    the compiler now is the <literal>haskellPackages.ghcWithPackages</literal>
    function. The <link
    xlink:href="http://nixos.org/nixpkgs/manual/#users-guide-to-the-haskell-infrastructure">User's
    Guide to the Haskell Infrastructure</link> provides more information about
    this subject.
  </para>
</listitem>

<listitem>
  <para>
    All Haskell builds that have been generated with version 1.x of
    the <literal>cabal2nix</literal> utility are now invalid and need
    to be re-generated with a current version of
    <literal>cabal2nix</literal> to function. The most recent version
    of this tool can be installed by running
    <literal>nix-env -i cabal2nix</literal>.
  </para>
</listitem>

<listitem>
  <para>
    The <literal>haskellPackages</literal> set in Nixpkgs used to have a
    function attribute called <literal>extension</literal> that users
    could override in their <literal>~/.nixpkgs/config.nix</literal>
    files to configure additional attributes, etc. That function still
    exists, but it's now called <literal>overrides</literal>.
  </para>
</listitem>

<listitem>
  <para>
    The OpenBLAS library has been updated to version
    <literal>0.2.14</literal>. Support for the
    <literal>x86_64-darwin</literal> platform was added. Dynamic
    architecture detection was enabled; OpenBLAS now selects
    microarchitecture-optimized routines at runtime, so optimal
    performance is achieved without the need to rebuild OpenBLAS
    locally. OpenBLAS has replaced ATLAS in most packages which use an
    optimized BLAS or LAPACK implementation.
 </para>
</listitem>

<listitem>
  <para>
    The <literal>phpfpm</literal> is now using the default PHP version
    (<literal>pkgs.php</literal>) instead of PHP 5.4 (<literal>pkgs.php54</literal>).
  </para>
</listitem>

<listitem>
  <para>
    The <literal>locate</literal> service no longer indexes the Nix store
    by default, preventing packages with potentially numerous versions from
    cluttering the output. Indexing the store can be activated by setting
    <option>services.locate.includeStore = true</option>.
  </para>
</listitem>

<listitem>
  <para>
    The Nix expression search path (<envar>NIX_PATH</envar>) no longer
    contains <filename>/etc/nixos/nixpkgs</filename> by default. You
    can override <envar>NIX_PATH</envar> by setting
    <option>nix.nixPath</option>.
  </para>
</listitem>

<listitem>
  <para>
    Python 2.6 has been marked as broken (as it no longer recieves
    security updates from upstream).
  </para>
</listitem>

<listitem>
  <para>
    Any use of module arguments such as <varname>pkgs</varname> to access
    library functions, or to define <literal>imports</literal> attributes
    will now lead to an infinite loop at the time of the evaluation.
  </para>

  <para>
    In case of an infinite loop, use the <command>--show-trace</command>
    command line argument and read the line just above the error message.

<screen>
$ nixos-rebuild build --show-trace
…
while evaluating the module argument `pkgs' in "/etc/nixos/my-module.nix":
infinite recursion encountered
</screen>
  </para>


  <para>
    Any use of <literal>pkgs.lib</literal>, should be replaced by
    <varname>lib</varname>, after adding it as argument of the module.  The
    following module

<programlisting>
{ config, pkgs, ... }:

with pkgs.lib;

{
  options = {
    foo = mkOption { … };
  };
  config = mkIf config.foo { … };
}
</programlisting>

   should be modified to look like:

<programlisting>
{ config, pkgs, lib, ... }:

with lib;

{
  options = {
    foo = mkOption { <replaceable>option declaration</replaceable> };
  };
  config = mkIf config.foo { <replaceable>option definition</replaceable> };
}
</programlisting>
  </para>

  <para>
    When <varname>pkgs</varname> is used to download other projects to
    import their modules, and only in such cases, it should be replaced by
    <literal>(import &lt;nixpkgs&gt; {})</literal>.  The following module

<programlisting>
{ config, pkgs, ... }:

let
  myProject = pkgs.fetchurl {
    src = <replaceable>url</replaceable>;
    sha256 = <replaceable>hash</replaceable>;
  };
in

{
  imports = [ "${myProject}/module.nix" ];
}
</programlisting>

    should be modified to look like:

<programlisting>
{ config, pkgs, ... }:

let
  myProject = (import &lt;nixpkgs&gt; {}).fetchurl {
    src = <replaceable>url</replaceable>;
    sha256 = <replaceable>hash</replaceable>;
  };
in

{
  imports = [ "${myProject}/module.nix" ];
}
</programlisting>
  </para>

</listitem>

</itemizedlist>
</para>


<para>Other notable improvements:

<itemizedlist>

  <listitem><para>The nixos and nixpkgs channels were unified,
    so one <emphasis>can</emphasis> use <literal>nix-env -iA nixos.bash</literal>
    instead of <literal>nix-env -iA nixos.pkgs.bash</literal>.
    See <link xlink:href="https://github.com/NixOS/nixpkgs/commit/2cd7c1f198">the commit</link> for details.
  </para></listitem>

  <listitem>
    <para>
      Users running an SSH server who worry about the quality of their
      <literal>/etc/ssh/moduli</literal> file with respect to the
      <link
      xlink:href="https://stribika.github.io/2015/01/04/secure-secure-shell.html">vulnerabilities
      discovered in the Diffie-Hellman key exchange</link> can now
      replace OpenSSH's default version with one they generated
      themselves using the new
      <option>services.openssh.moduliFile</option> option.
      </para>
  </listitem>

  <listitem> <para>
    A newly packaged TeX Live 2015 is provided in <literal>pkgs.texlive</literal>,
    split into 6500 nix packages. For basic user documentation see
    <link xlink:href="https://github.com/NixOS/nixpkgs/blob/release-15.09/pkgs/tools/typesetting/tex/texlive-new/default.nix#L1"
      >the source</link>.
    Beware of <link xlink:href="https://github.com/NixOS/nixpkgs/issues/9757"
      >an issue</link> when installing a too large package set.

    The plan is to deprecate and maybe delete the original TeX packages
    until the next release.
  </para> </listitem>

  <listitem><para>
    <option>buildEnv.env</option> on all Python interpreters
    is now available for nix-shell interoperability.
  </para> </listitem>
</itemizedlist>

</para>

</section>
