Awesome WM ignores input in non-us layout
The bug is apparently in this https://bugs.archlinux.org/task/29123.
Source: https://awesome.naquadah.org/bugs/index.php?do=details&task_id=982
I'm duplicating a comment to the accepted answer here for better visibility.
A workaround is to edit file /usr/share/X11/xkb/compat/basic
and remove or comment out the lines:
group 2 = AltGr;
group 3 = AltGr;
group 4 = AltGr;
as suggested here