Recently I've been trying out GNOME3 on my workstation. While it is visually appealing to me (looks a lot like OS X) and the overall experience is, after some tweaking, ok for me I encountered a very specific problem: as a user of the us variant
intl-altgr I wasn't able to input umlauts in Emacs as well as a few other apps. Emacs even gave me an error message:
<S-dead-diaeresis> is undefined.
After searching the interwebs for a while I found an Ubuntu bug report stating that when setting
XMODIFIERS to an empty value all works again. After trying I could confirm that. This I had a look at the unmodified value of this variable: its value was
@im=ibus. This gave me the right keyword to search for:
ibus. IBus (Intelligent Input Bus)
is an open source input framework for Linux and Unix. It basically is an abstraction to enter „foreign characters.“
After reading that description it was clear to me that this was the reason for my problems. So I've been looking for how to disable IBus in GNOME and it turns out that there is a way to do this with this command:
</pre>$ gsettings set org.gnome.settings-daemon.plugins.keyboard active false
After restarting GNOME I now was able to enter my composed characters (such as umlauts) normally again.