<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-17.09">

<title>Release 17.09 (“Hummingbird”, 2017/09/??)</title>

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

<itemizedlist>
  <listitem>
    <para>
      The user handling now keeps track of deallocated UIDs/GIDs. When a user
      or group is revived, this allows it to be allocated the UID/GID it had before.
      A consequence is that UIDs and GIDs are no longer reused.
    </para>
  </listitem>
  <listitem>
    <para>
      The module option <option>services.xserver.xrandrHeads</option> now
      causes the first head specified in this list to be set as the primary
      head. Apart from that, it's now possible to also set additional options
      by using an attribute set, for example:
<programlisting>
{ services.xserver.xrandrHeads = [
    "HDMI-0"
    {
      output = &quot;DVI-0&quot;;
      primary = true;
      monitorConfig = ''
        Option &quot;Rotate&quot; &quot;right&quot;
      '';
    }
  ];
}
</programlisting>
      This will set the <literal>DVI-0</literal> output to be the primary head,
      even though <literal>HDMI-0</literal> is the first head in the list.
    </para>
  </listitem>
</itemizedlist>

<para>The following new services were added since the last release:</para>

<itemizedlist>
  <listitem>
    <para></para>
  </listitem>
</itemizedlist>


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

<itemizedlist>
  <listitem>
    <para>
      Top-level <literal>idea</literal> package collection was renamed.
      All JetBrains IDEs are now at <literal>jetbrains</literal>.
    </para>
  </listitem>
  <listitem>
    <para>
      <literal>flexget</literal>'s state database cannot be upgraded to its
      new internal format, requiring removal of any existing
      <literal>db-config.sqlite</literal> which will be automatically recreated.
    </para>
  </listitem>
</itemizedlist>


<para>Other notable improvements:</para>

<itemizedlist>

  <listitem>
    <para>
      Modules can now be disabled by using <link
      xlink:href="https://nixos.org/nixpkgs/manual/#sec-replace-modules">
      disabledModules</link>, allowing another to take it's place.  This can be
      used to import a set of modules from another channel while keeping the
      rest of the system on a stable release.
    </para>
  </listitem>
  <listitem>
    <para>
      Updated to FreeType 2.7.1, including a new TrueType engine.
      The new engine replaces the Infinality engine which was the default in
      NixOS. The default font rendering settings are now provided by
      fontconfig-penultimate, replacing fontconfig-ultimate; the new defaults
      are less invasive and provide rendering that is more consistent with
      other systems and hopefully with each font designer's intent. Some
      system-wide configuration has been removed from the Fontconfig NixOS
      module where user Fontconfig settings are available.
    </para>
  </listitem>

</itemizedlist>

</section>
