8.1 hang when adding an instrument plugin to MIDI track [SOLVED]

[EDIT] Old pipewire = brokenness. [/EDIT]

Hi - I have a machine running completely up-to-date KDE Neon with Ardour 8.1 downloaded today to try to diagnose a crash when I add a midi instrument plugin to a MIDI track. I have tried the latest stable 8.1 and then got the below diagnostic output from the latest nightly debug build.

Linux 6.2.0-1017-lowlatency #17~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Thu Nov 2 18:30:14 UTC 2 x86_64 x86_64 x86_64 GNU/Linux

pipewire 0.3.48

Attempting to add a MIDI instrument to the MIDI track results in the following (that repeats forever…)

0x7fdfe5ffb640 (AudioEngine 1) 19346915280 DEBUG::LTC: LTC resync_xrun()
0x7fdfe5ffb640 (AudioEngine 1) 19346915465 PBD::DEBUG::AbstractUI: gui: no space in per thread pool for request of type 8
0x7fdfe5ffb640 (AudioEngine 1) 19346915518 DEBUG::TXLTC: reset
0x7fdfe5ffb640 (AudioEngine 1) 19346915544 PBD::DEBUG::AbstractUI: gui: no space in per thread pool for request of type 8
0x7fdfe5ffb640 (AudioEngine 1) 19346915564 PBD::DEBUG::AbstractUI: gui: no space in per thread pool for request of type 1
0x7fdfe5ffb640 (AudioEngine 1) 19346915577 PBD::DEBUG::AbstractUI: gui: no space in per thread pool for request of type 1
0x7fdfe5ffb640 (AudioEngine 1) 19346936575 DEBUG::LTC: LTC resync_xrun()
0x7fdfe5ffb640 (AudioEngine 1) 19346936719 PBD::DEBUG::AbstractUI: gui: no space in per thread pool for request of type 8
0x7fdfe5ffb640 (AudioEngine 1) 19346936764 DEBUG::TXLTC: reset
0x7fdfe5ffb640 (AudioEngine 1) 19346936786 PBD::DEBUG::AbstractUI: gui: no space in per thread pool for request of type 8
0x7fdfe5ffb640 (AudioEngine 1) 19346936812 PBD::DEBUG::AbstractUI: gui: no space in per thread pool for request of type 1
0x7fdfe5ffb640 (AudioEngine 1) 19346936827 PBD::DEBUG::AbstractUI: gui: no space in per thread pool for request of type 1

The program hangs, the GUI does not respond, and the application has to be manually terminated. I am happy to run more/different diagnostics if you let me know what to do.

Thanks,

Please start there. Use the ALSA backend in Ardour and see if you have the same issue.

Also, what is the instrument plugin you’re trying to add?

Thanks, Paul. It does indeed work fine with ALSA. Regarding the plugin, I tried Surge, Vaporizer2, and Helm. All caused the problem, or, well, 8.1 + pipewire 0.3.48 does with any midi instrument.

When I was troubleshooting, I thought I had the same pipewire version on my Arch Linux box (which does not have this problem with Ardour 8.1) , but in fact that pw version is 0.3.84 not 48. :stuck_out_tongue: I will have to figure out some kind of bandaid for my KDE machines. (These are lab machines required for a class next semester, so … ugh. I think I just recommend they use it with ALSA?)

Thanks, and sorry for not troubleshooting better before posting.

This is a known bug with an old version of pipewire.

Fixed with pipewire 1.0.

Yup. Ubuntu LTS base biting me on the butt again.