I have a project with a deps.edn naming overtone 0.10.6 as a dependency. When running clj in this project, after executing (use 'overtone.live), running this code snippet: https://github.com/overtone/overtone/blob/f6d414f884f1b6d3166195b49276174efddf2cf2/src/overtone/examples/synthesis/filters.clj#L12-L14 gives me the following error:

exception in GraphDef_Recv: UGen 'MouseX' not installed.
#<synth-node[loading]: user/audition-synth 33>
user=> *** ERROR: SynthDef user/audition-synth not found
FAILURE IN SERVER /s_new SynthDef not found

Executing the same thing in CIDER does uhm… nothing? It returns an audition-synth but does not output any sound

If I leave out mouse-x it works fine

Is that a Linux thing? I do have /usr/share/SuperCollider/HelpSource/Classes/MouseX.schelp on my system

And using the MouseX UGen in scide works

Open a ticket please. I think this could be a internal synth issue. How did you boot to sc?