dirt is stored in the global variable ~dirt, so you need to write
~dirt.soundLibrary.addSynth(\panic, (play: { ~dirt.orbits.do(_.freeSynths) }));
dirt is stored in the global variable ~dirt, so you need to write
~dirt.soundLibrary.addSynth(\panic, (play: { ~dirt.orbits.do(_.freeSynths) }));