Using the x2go client in Yosemite

This was complex to get going, and now that there is a fix for the opennx client, it's probably a better bet, but in case you want to try, here's where I got to:

1. Logging in from the client sometimes fails after the server has been rebooted. This seems to be a problem with a left-over lx terminal socket file that doesn't get cleaned up properly. To fix it, I used

ls -a /tmp
rm /tmp/.lxterminal-socket:<socketno>-<username>

1. Keyboard mappings get messed up. To fix this, I used two separate hints. The first is from Daniel Lange: First, on your mac, open an xterm (by starting up xquartz, which you can do easily by starting the x2goclient). In that terminal do

xmodmap -pke > localxmodmap

Then copy (e.g. by sftp or scp) that localxmodmap to your server. In your home directory, check if there is already a .Xmodmap file. If there is, you may need to merge the new one with it - sorry, can't help with that. If there isn't, copy localxmodmap to .Xmodmap. However you're not finished. Now (thanks to ato on stackoverflow), you need to append to the .Xmodmap file:

!
! Now reset all the modifiers too
!
clear shift
clear lock
clear control
clear mod1
clear mod2
clear mod3
clear mod4
clear mod5
add shift = Shift_L Shift_R
add lock = Caps_Lock
add control = Control_L Control_R
add mod1 = Alt_L Alt_R
add mod2 = Meta_L Meta_R

So far, almost all applications seem to work with this. The exception is virtualbox, which still has (for me) corrupted keyboard settings.