A ChucK voice that never reaches dac produces silence with no error

If a UGen chain is patched to blackhole (the null sink) or simply never connected to dac, the voice is silent and no error is reported. blackhole is intentional for control/analysis UGens (LFOs, envelope followers) that should not produce audio output. For any audio voice, a continuous path from the UGen to dac is required. Combined with the no-time-advance bug, this is a main source of unexplained silence in ChucK.

Examples

SinOsc s => blackhole; — silent, no error. Fix: SinOsc s => dac;.

Assessment

State why a ChucK voice patched to blackhole is silent with no error, and give the fix.