How to make the Alt key work ?
If you find yourself unable to use Inkscape functions that require the alt key (i.e. option key) such as Alt+D to create a clone or Alt+Click to select under, you will need to turn off the “Emulate three button mouse” under the Input Preferences for X11. If you still cannot get it to work you can try using a keyboard mapping file for X11 (the environment Inkscape is running in) called an xmodmap.
