I was having some problems with the ALT key on my Macbook in Inkscape. To adjust the text space and kerning in Inkscape you need to use the keyboard. This was not working, so I was stuck. Luckily, as usually I was not alone. I found a way to map the keys to work correctly under X11 and furthermore it makes the CMD key act as the CTRL as well. Double bonus.
Create the file
keycode 63 = Control_L keycode 60 = Alt_L keycode 66 = Alt_L clear mod1 clear Control add mod1 = Alt_L add Control = Control_L
Did this help you out? It took me a few days to piece together all this information together, I hope this saves you some time (who knows, maybe the future me will be thankful I wrote this down). Let me know your thoughts. email@example.com