There turn out to be some annoying side-effects of disabling xkbcomp. The problems I was were that the alt key didn't work in xterm or when switching virtual terminals using crtl-alt-F1 (see bug #111372).
I have a little more data on how xkbcomp is invoked. By changing /usr/bin/xkbcomp into a shell script I was able to determine that during login it is run 3 times.
1. |-gdm(14821)---gdm(14822)---Xorg(14863)---sh(9127)---xkbcomp(9128)---xkbcomp(9129)---pstree(9131)
Called with args: -w 1 -R/usr/share/X11/xkb -xkm - -em1 The XKEYBOARD keymap com
piler (xkbcomp) reports: -emp > -eml Errors from xkbcomp are not fatal to the X
server /var/lib/xkb/server-0.xkm
2. |-gdm(14821)---gdm(14822)-+-Xorg(14863)
| `-Xsession(9233)---xkbcomp(9251)---xkbcomp(9252)---pstree(9254)
Called with args: /home/ota/.keymap.xkb :0
3. |-gdm(14821)---gdm(14822)-+-Xorg(14863)
| `-sh(9233)-+-ssh-agent(9293)
| |-xfce4-session(9338)---xfce-mcs-manage(9341)---xkbcomp(9342)---xkbcomp(9343)---pstree+
| `-xscreensaver(9304)
Called with args: -I -I/etc/X11/xkb -xkm /tmp/fileCbGof2 /tmp/fileaVT6TK
The second of these is due to my ~/.xprofile invoking xkbcomp "by hand".
Reviewing Oliver's strace output, it seems that xfce-mcs-manager reads the output of xkbcomp (step 3 above) and sends it to the X server.
There turn out to be some annoying side-effects of disabling xkbcomp. The problems I was were that the alt key didn't work in xterm or when switching virtual terminals using crtl-alt-F1 (see bug #111372).
I have a little more data on how xkbcomp is invoked. By changing /usr/bin/xkbcomp into a shell script I was able to determine that during login it is run 3 times.
1. |-gdm(14821) ---gdm( 14822)- --Xorg( 14863)- --sh(9127) ---xkbcomp( 9128)-- -xkbcomp( 9129)-- -pstree( 9131) share/X11/ xkb -xkm - -em1 The XKEYBOARD keymap com xkb/server- 0.xkm
Called with args: -w 1 -R/usr/
piler (xkbcomp) reports: -emp > -eml Errors from xkbcomp are not fatal to the X
server /var/lib/
2. |-gdm(14821) ---gdm( 14822)- +-Xorg( 14863) 9233)-- -xkbcomp( 9251)-- -xkbcomp( 9252)-- -pstree( 9254) .keymap. xkb :0
| `-Xsession(
Called with args: /home/ota/
3. |-gdm(14821) ---gdm( 14822)- +-Xorg( 14863) -+-ssh- agent(9293) session( 9338)-- -xfce-mcs- manage( 9341)-- -xkbcomp( 9342)-- -xkbcomp( 9343)-- -pstree+ 9304)
| `-sh(9233)
| |-xfce4-
| `-xscreensaver(
Called with args: -I -I/etc/X11/xkb -xkm /tmp/fileCbGof2 /tmp/fileaVT6TK
The second of these is due to my ~/.xprofile invoking xkbcomp "by hand".
Reviewing Oliver's strace output, it seems that xfce-mcs-manager reads the output of xkbcomp (step 3 above) and sends it to the X server.