Comment 158 for bug 1218322

Sorry it doesn't work foo me.. deleted lines in /etc/default/keyboard, install ppa, update-upgrade and restart. Changing through Region settings does not allow me set Shift-whatever.
Gnome-tweak-tool can be set to Alt - Shift and indicator changes but not the keyboard. Also pressing Alt-Shift in Gnome tweak (while Alt-Shift is set to change layout) crashes the tweak tool with segfault. in dmesg i see after the crash (
dconf worker[2633]: segfault at 0 ip 00007f216cdde1c0 sp 00007f215bffec48 error 4 in libpthread-2.17.so