[Ardour-Dev] ardour 2.8.4 + jack 1.9.3 + export = stuck transport?

[Fernando Lopez-Lezcano]

Hey, I'm seeing a weird issue here. Start jack (jack2 1.9.3) in
qjackctl, start ardour (2.8.4), create one track, record some stuff in
there, rewind, playback, etc. Go to "Session", "Export", "Export Session
to Audiofile", select specific channels, select destination file, press
export. Export happens. After that playback does not work anymore,
pressing on "Play" does not do anything. 

Save session, quit ardour, restart ardour, load session. "Play" still
does not work (!). Disconnect from jack, _stop_ jack, start jack again,
reconnect. Playback works again (!!)

Apparently something (transport control) is left in a weird state inside
jack. Very weird... 

[just confirmed that it is somewhat transport control and jack related.
If ardour/jack2 is/are in that weird state and I start Hydrogen it won't
play either]

-- Fernando