<part id="running-mutter">

  <title>Running Mutter</title>

  <partintro>

    <section id="environment-variables">
      <title>Environment Variables</title>

      <para>
        Mutter automatically checks environment variables during
        its initialization. These environment variables are meant
        as debug tools or overrides for default behaviours:
      </para>

      <variablelist>
        <varlistentry>
          <term>MUTTER_VERBOSE</term>
          <listitem>
            <para>Enable verbose mode, in which more information is printed to the console. Mutter needs to be built with the --enable-verbose-mode option (enabled by default). For more fine-grained control of the output, see meta_add_verbose_topic().</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term>MUTTER_DEBUG</term>
          <listitem>
            <para>Traps and prints X errors to the console.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term>MUTTER_G_FATAL_WARNINGS</term>
          <listitem>
            <para>Causes any logging from the domains Mutter, Gtk, Gdk, Pango or GLib to terminate the process (only when using the log functions in GLib).</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term>MUTTER_USE_LOGFILE</term>
          <listitem>
            <para>Log all messages to a temporary file.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term>MUTTER_DEBUG_XINERAMA</term>
          <listitem>
            <para>Log extra information about support of the XINERAMA extension.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term>MUTTER_DEBUG_SM</term>
          <listitem>
            <para>Log extra information about session management.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term>MUTTER_DEBUG_BUTTON_GRABS</term>
          <listitem>
            <para>Log extra information about button grabs.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term>MUTTER_SYNC</term>
          <listitem>
            <para>Call XSync after each X call.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term>MUTTER_DISPLAY</term>
          <listitem>
            <para>Name of the X11 display to use.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term>META_DISABLE_MIPMAPS</term>
          <listitem>
            <para>Disable use of mipmaps for the textures that back window pixmaps.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term>MUTTER_USE_STATIC_GRAVITY</term>
          <listitem>
            <para>Enable support for clients with static bit-gravity.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term>MUTTER_WM_CLASS_FILTER</term>
          <listitem>
            <para>Comma-separated list of WM_CLASS names to which to restrict Mutter to.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term>MUTTER_DISABLE_FALLBACK_COLOR</term>
          <listitem>
            <para>Disable fallback for themed colors, for easier detection of typographical errors.</para>
          </listitem>
        </varlistentry>
      </variablelist>

    </section>

  </partintro>
</part>
