It seems like Arch is currently offering Jack and qjackctl packages that are not compatible.
The Jack authors changed one some command line options in 0.118. '-R' for realtime is no longer available as realtime is now the default, and the new '-r' means 'no realtime'. Qjackctl 0.3.6 is aware of this, but won't work well with Jack 0.116 which is still the one available from Arch. In other words, the update of qjackctl was probably a bit premature. Ciao, -- FA O tu, che porte, correndo si ? E guerra e morte !
