Everytime I run X manually, I get the following error message:
----
The XKEYBOARD keymap compiler (xkbcomp) reports:
> Warning:          Type "ONE_LEVEL" has 1 levels, but <RALT> has 2 symbols
>                   Ignoring extra symbols
Errors from xkbcomp are not fatal to the X server
----

Since this is really annoying to me, I tracked it down to:

/usr/share/X11/xkb/symbols/level3:
----
// the default behavior is for the right Alt key (AltGr) to generate the
// third engraved symbol
default partial modifier_keys
xkb_symbols "ralt_switch" {
  key <RALT> {
    type[Group1]="ONE_LEVEL",
    symbols[Group1] = [ ISO_Level3_Shift ]
    };
  modifier_map Mod5   { ISO_Level3_Shift };
};
----

and /usr/share/X11/xkb/symbols/altwin:
---
partial modifier_keys 
xkb_symbols "meta_alt" {
    key <LALT> {        [       Alt_L,  Meta_L          ]       };
    key <RALT> {        [       Alt_R,  Meta_R          ]       };
    modifier_map Mod1   { Alt_L, Alt_R, Meta_L, Meta_R };
};
----

Here you see that two symbols are assigned to RALT, which is defined as
ONE_LEVEL. Commenting out the RALT line in /usr/share/X11/xkb/symbols/altwin
helps, as well as changing ONE_LEVEL to TWO_LEVEL in
/usr/share/X11/xkb/symbols/level3.

I don't know which one is the correct way. I only know that hundreds of people
have the same warnings (search the web for the message). It would be great if
that issue could be fixed. The Gentoo devs sent me here; see the related bug.


Related:
http://bugs.gentoo.org/show_bug.cgi?id=269931
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=291853

Reproducible: Always

Steps to Reproduce:
1. start X as root on the shell
2. watch the output

Actual Results:  
The XKEYBOARD keymap compiler (xkbcomp) reports:
> Warning:          Type "ONE_LEVEL" has 1 levels, but <RALT> has 2 symbols
>                   Ignoring extra symbols
Errors from xkbcomp are not fatal to the X server

Expected Results:  
No warning/error

I use  x11-apps/xkbcomp 1.0.5 and x11-apps/setxkbmap 1.0.4, xorg-server 1.5.3-r5, x11-libs/libxkbfile 1.0.5

My xorg.conf lists no keyboard configuration, but
/etc/hal/fdi/policy/10-keymap.fdi contains:

<?xml version="1.0" encoding="ISO-8859-1"?> <!-- -*- SGML -*- -->
<deviceinfo version="0.2">
  <device>
    <match key="info.capabilities" contains="input.keymap">
      <append key="info.callouts.add" type="strlist">hal-setup-keymap</append>
    </match>

    <match key="info.capabilities" contains="input.keys">
      <merge key="input.xkb.rules" type="string">base</merge>
      <merge key="input.x11_driver" type="string">evdev</merge>
      <merge key="input.xkb.layout" type="string">de</merge>
      <merge key="input.xkb.model" type="string">macintosh</merge>
    </match>
  </device>
</deviceinfo>