configuration.nix

    packageOverrides = super: {
      xorg = super.xorg // rec {
        xkeyboard_config_dvp = super.pkgs.lib.overrideDerivation super.xorg.xkeyboardconfig (old: {
          patches = [
            (builtins.toFile "ru-dvp.patch" ''
                --- xkeyboard-config-2.16-orig/symbols/ru       2014-12-11 01:56:38.000000000 +0300
                +++ xkeyboard-config-2.16/symbols/ru    2016-04-15 14:27:25.075214654 +0300
                @@ -719,3 +719,24 @@
                     key <TLDE> { [  bracketright,  bracketleft  ] };
                     key <BKSL> { [   Cyrillic_io,  Cyrillic_IO  ] };
                 };
                +partial default alphanumeric_keys
                +xkb_symbols "dvp" {
                +    include "ru(common)"
                +
                +    name[Group1]= "Russia";
                +
                +    key <AE01> {        [       numerosign, percent   ]       };
                +    key <AE02> {        [       quotedbl,   7         ]       };
                +    key <AE03> {        [       question,   5         ]       };
                +    key <AE04> {        [       slash,      3         ]       };
                +    key <AE05> {        [       parenleft,  1         ]       };
                +    key <AE06> {        [       equal,      9         ]       };
                +    key <AE07> {        [       asterisk,   0         ]       };
                +    key <AE08> {        [       parenright, 2         ]       };
                +    key <AE09> {        [       plus,       4         ]       };
                +    key <AE10> {        [       minus,      6         ]       };
                +    key <AE11> {        [       exclam,     8         ]       };
                +    key <AE12> {        [       semicolon,  colon     ]       };
                +    key <AB10> {        [       period,     comma     ]       };
                +    key <BKSL> {        [       backslash,  bar       ]       };
                +};
              '')
          ];
        });
        xorgserver = super.pkgs.lib.overrideDerivation super.xorg.xorgserver (old: {
          postInstall = ''
            rm -fr $out/share/X11/xkb/compiled
            ln -s /var/tmp $out/share/X11/xkb/compiled
            wrapProgram $out/bin/Xephyr \
              --set XKB_BINDIR "${xkbcomp}/bin" \
              --add-flags "-xkbdir ${xkeyboard_config_dvp}/share/X11/xkb"
            wrapProgram $out/bin/Xvfb \
              --set XKB_BINDIR "${xkbcomp}/bin" \
              --set XORG_DRI_DRIVER_PATH ${super.mesa}/lib/dri \
              --add-flags "-xkbdir ${xkeyboard_config_dvp}/share/X11/xkb"
            ( # assert() keeps runtime reference xorgserver-dev in xf86-video-intel and others
              cd "$dev"
              for f in include/xorg/*.h; do # */
                sed "1i#line 1 \"${old.name}/$f\"" -i "$f"
              done
            )
          '';
        }); 
        setxkbmap = super.pkgs.lib.overrideDerivation super.xorg.setxkbmap (old: {
          postInstall =
            ''
              mkdir -p $out/share
              ln -sfn ${xkeyboard_config_dvp}/etc/X11 $out/share/X11
            '';
        });
        xkbcomp = super.pkgs.lib.overrideDerivation super.xorg.xkbcomp (old: {
          configureFlags = "--with-xkb-config-root=${xkeyboard_config_dvp}/share/X11/xkb";
        });
      };
    };
  };