Double Free Crash with Midi Device

I’ve recently got started trying to use VCV Rack, and I quite like how the software looks, I think it will be good for my usecase. Unfortunately I’ve been experiencing very frequent crashes (every couple minutes or so).

MidiInJack::initialize: JACK server not running?
MidiOutJack::initialize: JACK server not running?
RtAudio pulse: NOT running realtime scheduling
free(): double free detected in tcache 2
Aborted (core dumped)

The above are the logs I get each time I take the actions needed to crash the software.

I am working on a Linux system using the provided linux binary, it’s a Manjaro system using proprietary nvidia drivers and a ryzen 7 that’s currently fully up to date. My midi device is an Akai MPK Mini Laptop Production Keyboard (the first one).

Whenever I start up the default template that comes with VCV and add a Midi Mapping module and attempt to map any of the dials on the device it appears to function correctly for a short while before crashing.

My small amount of testing seems to indicate that the crashes don’t occur without a midi device connected, nor during normal usage of the midi device, although I’m not certain of either of those claims.

What would be the next steps I could take to help diagnose this problem? Is there some verbose logging that I can turn on to provide to help track down the cause and turn this into a proper bug report so that it could be fixed?

Alternatively am I just missing something and there’s a simple fix for this that I’ve just missed because this is my first try using a MIDI device on Linux?

If you are a hacker type you should build VCV and the plugins for linux or macos to run under address sanitizer.

One thing you can do, also, is post the crash log. The VCV manual tells where to find this.

I found the logs. For whatever reason though I haven’t been able to recreate the crash today so I don’t have a proper crash log. I’ll keep trying to see if I can manage to replicate it again, but honestly if everything just works from here out I can’t say I’ll be entirely unhappy as a user. Although as a developer it’s always annoying to see a crash that then you don’t get info on.

I think the VCV folks are plenty busy, so if your issue goes away - great. Then down the road some other people will start to get this error and it will have to be dealt with.