Bug#482195: ev_calibrate doesn't start because it can't find /empty_cursor.xbm
The package xserver-xorg-input-evtouch provides a tool for calibration,
but it throws an X error because it doesn't find the file
Easy fix is to copy or create a symlink from
/usr/share/xf86-input-evtouch/empty_cursor.xbm to /.
What I simply do:
| sudo cp /usr/share/xf86-input-evtouch/empty_cursor.xbm /
| cd /usr/lib/xf86-input-evtouch
Other than that I can't seem to find this tool useful.