Could you try setting that configuration using setxkbmap utility?

(In reply to comment #1)
> Could you try setting that configuration using setxkbmap utility?
> 

What exactly should I supply to the setxkbmap utility?
What is the correct code for the macbook pro keymap?
 
This is the current "setxkbmap -print" output:

xkb_keymap {
        xkb_keycodes  { include "xfree86+aliases(qwerty)"       };
        xkb_types     { include "complete"      };
        xkb_compat    { include "complete"      };
        xkb_symbols   { include "pc(pc105)+ch(de_mac)+gb(mac):2+latam:3+level3(rwin_switch)"    };
        xkb_geometry  { include "pc(pc105)"     };
};

> What exactly should I supply to the setxkbmap utility?

setxkbmap -model macbook78 -layout 'ch,gb' -variant 'de_mac,mac' -option 'grp:alts_toggle' -option 'altwin:meta_win'

Didn't work: This is the error I get:

setxkbmap -model macbook78 -layout 'ch,gb' -variant 'de_mac,mac' -option 'grp:alts_toggle' -option 'altwin:meta_win'
Error loading new keyboard description

Good!

So, let's make it more complex:

setxkbmap -model macbook78 -layout 'ch,gb' -variant 'de_mac,mac' -option
 'grp:alts_toggle' -option 'altwin:meta_win' -print

and

setxkbmap -model macbook78 -layout 'ch,gb' -variant 'de_mac,mac' -option
 'grp:alts_toggle' -option 'altwin:meta_win' -print | xkbcomp - :0

> Good!
I like your attitude :-)

> 
> setxkbmap -model macbook78 -layout 'ch,gb' -variant 'de_mac,mac' -option
>  'grp:alts_toggle' -option 'altwin:meta_win' -print
> 

xkb_keymap {
        xkb_keycodes  { include "macintosh+macintosh(badmap)+aliases(qwerty)"  };
        xkb_types     { include "complete+numpad(mac)"  };
        xkb_compat    { include "complete"      };
        xkb_symbols   { include "pc(pc105)+macintosh_vndr/ch(de_mac)+inet(apple)+level3(enter_switch)+gb(mac):2+level3(ralt_switch_for_alts_toggle):1+level3(ralt_switch_for_alts_toggle):2+altwin(meta_win)+group(alts_toggle)+level3(rwin_switch)"    };
        xkb_geometry  { include "macintosh(macbook78)"  };
};

> and
> 
> setxkbmap -model macbook78 -layout 'ch,gb' -variant 'de_mac,mac' -option
>  'grp:alts_toggle' -option 'altwin:meta_win' -print | xkbcomp - :0
> 

Error:            No Symbols named "de_mac" in the include file "macintosh_vndr/ch"
                  Exiting
                  Abandoning symbols file "(null)"
Error:            success in unknown
                  Couldn't write keyboard description to :0

> Error:            No Symbols named "de_mac" in the include file
> "macintosh_vndr/ch"
>                   Exiting
>                   Abandoning symbols file "(null)"
> Error:            success in unknown
>                   Couldn't write keyboard description to :0
> 
That's an answer. Once you chosen model macbook78, the variants and layouts (listed in $macvendorlayouts in rules/base) are taken from the symbols/macintosh_vendor subdir. So I'd recommend chosing just layout 'ch' variant 'de'. Or - alternatively, local hack - removing 'ch' from the $macvendorlayouts list.

HTH

OK thanks, here are the results:

fabio@fabio-laptop:$ setxkbmap -model macbook78 -layout 'ch' -variant 'de' -option 'grp:alts_toggle' -option 'altwin:meta_win'

fabio@fabio-laptop:$ setxkbmap -print
xkb_keymap {
        xkb_keycodes  { include "macintosh+macintosh(badmap)+aliases(qwerty)"   };
        xkb_types     { include "complete+numpad(mac)"  };
        xkb_compat    { include "complete"      };
        xkb_symbols   { include "pc(pc105)+macintosh_vndr/ch(de)+inet(apple)+level3(enter_switch)+level3(ralt_switch_for_alts_toggle)+altwin(meta_win)+group(alts_toggle)+level3(rwin_switch)"     };
        xkb_geometry  { include "macintosh(macbook78)"  };
};

Seems to work (?)

> Seems to work (?)
Great! Hopefully the resulting layout is not to far from your expectations.