Hi, I have the same problem (I am using Ubuntu 16.04).
I cannot update anymore citra on my linux distribution. Is there any way to avoid installing a new distribution to be able again to use the latest citra build? Maybe citra could use a flatpak approach (https://flatpak.org/) or simular to distribute linux versions of citra in future?
I think that it is understandable that upgrading/re-installing a new OS is not a painless procedure, and many people cannot allow that due to other incompatibilities that could be arise in other applications. I was baffled In particular since the updated distribution needed to run citra (Ubuntu 18.04) was not even yet stable at the time of the switch …
Thank you for all your work!