Hmm... That wiki page you referred to was last edited 11 years ago and is obsolete to a large extent.
Today, on an Ubuntu system, it's normally GTK (not IBus, so I'm closing this bug report) which deals with rules in the ~/.XCompose file. I can confirm that GTK does not seem to be able to handle multi character strings. But if I switch to XIM it works for me.
* Open Language Support and change the "Keyboard input method
system" to "XIM"
* Reboot
Please note, though, that replacing "IBus" with "XIM" may result in other subtle issues.
Thanks for your report!
Hmm... That wiki page you referred to was last edited 11 years ago and is obsolete to a large extent.
Today, on an Ubuntu system, it's normally GTK (not IBus, so I'm closing this bug report) which deals with rules in the ~/.XCompose file. I can confirm that GTK does not seem to be able to handle multi character strings. But if I switch to XIM it works for me.
* Open Language Support and change the "Keyboard input method
system" to "XIM"
* Reboot
Please note, though, that replacing "IBus" with "XIM" may result in other subtle issues.