XKBは私のカスタムレイアウトを認識しません。

Lubuntu 18.04用のカスタムColemakベースのキーボードレイアウト（ファイル名「brc」）を作成し、それを/usr/share/X11/xkb/symbolsにコピーしました。

default partial
xkb_symbols "basic" {
    name[Group1]= "brc";

    // Alphanumeric section
    key <TLDE> { [   apostrophe,        quotedbl,        notsign,          notsign ] };
    key <AE01> { [            1,          exclam,    onesuperior,   exclamdown ] };
    key <AE02> { [            2,              at,    twosuperior,          onehalf ] };
    key <AE03> { [            3,      numbersign,  threesuperior,    threequarters ] };
    key <AE04> { [            4,          dollar,       sterling,       onequarter ] };
    key <AE05> { [            5,         percent,           cent,     threeeighths ] };
    key <AE06> { [            6,  dead_diaeresis,        notsign,        diaeresis ] };
    key <AE07> { [            7,       ampersand,      braceleft,     seveneighths ] };
    key <AE08> { [            8,        asterisk,    bracketleft,        trademark ] };
    key <AE09> { [            9,       parenleft,   bracketright,        plusminus ] };
    key <AE10> { [            0,      parenright,     braceright,           degree ] };
    key <AE11> { [        minus,      underscore,         endash,     questiondown ] };
    key <AE12> { [        equal,            plus,        section,      dead_ogonek ] };
    key <AE13> { [ bracketright,      braceright,      masculine,        masculine ] };
    key <BKSP> { [    BackSpace,       BackSpace,      BackSpace,        BackSpace ] };

    key <AD01> { [            q,               Q,          slash,            slash ] };
    key <AD02> { [            w,               W,       question,         question ] };
    key <AD03> { [            f,               F,       EuroSign,         EuroSign ] };
    key <AD04> { [            p,               P,          thorn,            THORN ] };
    key <AD05> { [            g,               G                                   ] }; 
    key <AD06> { [            j,               J,            yen                   ] };
    key <AD07> { [            l,               L                                   ] };
    key <AD08> { [            u,               U                                   ] };
    key <AD09> { [            y,               Y,         oacute,           Oacute ] };
    key <AD10> { [     ccedilla,        Ccedilla,                                  ] };
    key <AD11> { [   dead_acute,      dead_grave,         acute,             grave ] };
    key <AD12> { [  bracketleft,       braceleft,    ordfeminine,      dead_macron ] };

    key <AC01> { [            a,               A,             ae,               AE ] }; 
    key <AC02> { [            r,               R,     registered,       registered ] };
    key <AC03> { [            s,               S                                   ] };
    key <AC04> { [            t,               T                                   ] };
    key <AC05> { [            d,               D                                   ] };
    key <AC06> { [            h,               H                                   ] };
    key <AC07> { [            n,               N                                   ] };
    key <AC08> { [            e,               E                                   ] };
    key <AC09> { [            i,               I                                   ] };
    key <AC10> { [            o,               O,             oe,           OE     ] };
    key <AC11> { [   dead_tilde, dead_circumflex,     asciitilde,     asciicircum  ] };
    key <AC12> { [        slash,        question,   questiondown                   ] };

    key <AB01> { [            z,               Z,  guillemotleft                   ] };
    key <AB02> { [            x,               X, guillemotright                   ] };
    key <AB03> { [            c,               C       copyright,        copyright ] }; 
    key <AB04> { [            v,               V                                   ] }; 
    key <AB05> { [            b,               B                                   ] };
    key <AB06> { [            k,               K                                   ] };
    key <AB07> { [            m,               M,             mu,               mu ] };
    key <AB08> { [        comma,            less                                   ] };
    key <AB09> { [       period,         greater                                   ] };
    key <AB10> { [    semicolon,           colon                                   ] }; 

    key <SPCE> { [        space,           space,          space,     nobreakspace ] };

// Configures the "," for the numeric keypad
    include "kpdl(comma)"

// Configures the use of the AltGr key
    include "level3(ralt_switch)"
};

また、/usr/share/X11/xkb/rulesで次のファイルを変更しました。

evdev.xmlから

    <layout>
      <configItem>
        <name>brc</name>
        <shortDescription>custom-clmk</shortDescription>
        <description>custom-colemak-abnt2</description>
        <languageList>
           <iso639Id>por</iso639Id>
        </languageList>
      </configItem>
      <variantList/>
    </layout>

evdev.lstから

! layout
  brc             abnt2+colemak

結果は次のとおりです。

~$ setxkbmap -v brc
Warning! Multiple definitions of keyboard layout
         Using command line, ignoring X server
Trying to build keymap using the following components:
keycodes:   evdev+aliases(qwerty)
types:      complete
compat:     complete
symbols:    pc+brc+inet(evdev)
geometry:   pc(pc105)
Error loading new keyboard description

また、これは私の現在のレイアウトです。

~$ setxkbmap -v
Trying to build keymap using the following components:
keycodes:   evdev+aliases(qwerty)
types:      complete
compat:     complete
symbols:    pc+br+inet(evdev)
geometry:   pc(pc105)

xkbに自分のカスタムレイアウトを認識させるにはどうすればよいですか？