Hello Guix!

For the past few months I've been unable to use qjackctl, it would
freeze X all together on startup. It seems to happen only in tiling
window manager though. But, it looks like people upstream have found the
problem and disabling xunique fixes it!
See https://github.com/rncbc/qjackctl/issues/13.

The bug mentions qsynth too, I'll check if it has the same problem.

Thanks!
Pierre