setxkbmap -query fails with RANDR/RRGetOutputInfo error

I was trying to run
  setxkbmap -query
and am getting this error:

 X Error of failed request:  BadRROutput (invalid Output parameter)
  Major opcode of failed request:  141 (RANDR)
  Minor opcode of failed request:  9 (RRGetOutputInfo)
  Serial number of failed request:  12
  Current serial number in output stream:  12

But, if I start emacs or firefox before the setxkbmap command, it works
fine.  This is on amd64/10.1/ctwm/startx with no custom .xsession or .xinitrc.

I see that /var/log/Xorg.0.log has
 [  2358.120] (**) Option "Protocol" "standard"
 [  2358.120] (**) Option "XkbRules" "base"
 [  2358.120] (**) Option "XkbModel" "pc105"
 [  2358.120] (**) Option "XkbLayout" "us"

which is what should be returned normally
 # setxkbmap -query
 rules:      base
 model:      pc105
 layout:     us

Any suggestions?  I'll submit a PR if it would be helpful.

Thanks