[Waveform] MIDI track output completely non-functional on Linux

[lfont]

Hi,

I'm running Waveform 13.5.25 on Linux (Debian Trixie, PipeWire 1.4.9 / WirePlumber 0.5.12) and MIDI output to external devices does not work at all — no MIDI events are ever sent during playback, regardless of device assignment.

I discovered this while working on a custom controller script for the Arturia MiniLab3. sendMidiToDevice() was silently doing nothing, and investigating further revealed that MIDI out is broken at the track level too.

Some findings:
- The device (Midi Through Port-0: for testing purpose) is correctly enumerated, enabled, and opened by Waveform
- strace on the Waveform process during playback shows zero ioctl calls to /dev/snd/seq — the engine never writes to the ALSA sequencer
- aseqdump monitoring the target port during playback receives zero events

Is this a known issue on Linux? Is MIDI external output expected to work in Waveform 13?