I'm running the ardour on Kinetic and qjackctl with pipewire-jack runs flawlessly. I learned about qpwgraph here and I'm happily using it.
But: I had to run "pw-jack qjackctl" because jack2 was installed, and jack2 was installed because of qjackctl. If it is a build dependency it should be just this, a build-dependency. The dependency then should be (jack2 | pipewire-jack). Also, I didn't check but it should be possible to build qjackctl with the headers from pipewire-jack so even the build-dependency could be changed. I consider this a bug because without jack2 on the system I would not have to run qjackctl through pw-jack. Best regards, g

