[SOLVED] Jack2 not working after update

edvard · 2022-01-17 06:19:32

I use Qjackctl to start a Jack2 process to run sound recording and effects software for my electric guitar. My computer has a built-in soundcard, but for interfacing with my guitar, I run a Behringer U-Phoria UMC202HD ("U192k" according to 'cat /proc/asound/cards') connected via USB. I can run Jack2 and PulseAudio side-by-side because I simply tell Pavucontrol to ignore the Behringer (a simple matter of un-checking the convenient selection box) and everything remains nice and separated; the computer soundcard and the Behringer unit are both connected to different inputs on my stereo system, so I can switch between either by simply selecting the desired sound source on the stereo. This arrangement has worked for the last 3 - 4 years under Debian, and I was pleased to find it worked the same manner under Arch with minimal fuss.

On 15 JAN 2022, I did a full system upgrade with 'pacman -Syu', and saw that the jack2 and jack2-dbus packages were upgraded from 1.9.19-2 to 1.9.20-1.
After that, I could not start Jack2 with Qjackctl; it would simply crash. I also tried Guitarix and Carla, but they both would say they couldn't start or connect to the Jack2 server. I do not have PipeWire installed. Don't go there (please).

This is what happens, and what I tried to fix the situation, as I did not immediately suspect the new version of Jack2:
- The Qjackctl window would open, but when I clicked the "Start" button, the window would say "Starting" and after a second or two, it would auto-close.
- If I started Qjackctl again, the window would open, then immediately close.
- I noticed with 'ps -A' that a jackd process would remain running after the first time I opened Qjackctl.
- I killed the jackd process and started Qjackctl again; the window would open normally as the first time and I could change configurations, but would close a second or two after clicking "Start".
- If I started Qjackctl from a command line, the same as above would happen, but stderr would report only "segmentation fault".
- I tried making changes in the configuration, but nothing would change the behavior.
- I tried re-installing qjackctl, jack2, and alsa-lib; no change.
- I uninstalled both qjackctl and jack2 and compiled from source; no change.
- I tried to start Jack2 manually with '/usr/bin/jackd -dalsa -r48000 -p128 -n3 -Xseq -D -Chw:U192k -Phw:U192k'. It would start with no errors, but I couldn't connect to or view any inputs or outputs with Patchage or Carla, and Qjackctl would simply segfault.
- I tried to start Jack2 manually with 'usr/bin/jack_control', adding options according to https://wiki.archlinux.org/title/JACK_A … mple_setup
- I tried all the troubleshooting options detailed here: https://wiki.archlinux.org/title/JACK_A … ctl_errors. From there it appeared that PulseAudio was hoarding controls, so I killed PulseAudio and tried the afore-mentioned steps; no change.
- I tried switching kernels, thinking maybe a kernel module was at fault. I have both the 5.16.arch1-1 and 5.16.0-zen1-1-zen kernels installed; all these things happened on both.

After all that, I remembered that I can downgrade packages in Arch fairly easily, so I followed the advice at: https://wiki.archlinux.org/title/Downgrading_packages. I downgraded the jack2 and jack2-dbus packages back to version 1.9.19-2 and started Qjackctl; everything worked with no problems.

SO... I conclude that the new version of Jack2 is borked, but I wanted to ask here before I file a bug report:
- Is there something I may have missed in all my testing? If so, please let me know and I'll give it a shot. I'd like to be able to use the newest version.
- Have others had the same problem? If so, I'll file a bug report referencing this post.

Thanks!

Last edited by edvard (2022-01-20 01:56:16)

V1del · 2022-01-17 07:52:01

What's the contents of the segfault/coredump: https://wiki.archlinux.org/title/Core_d … _core_dump ?

edvard · 2022-01-17 10:34:04

[papa@arch-pc ~]$ qjackctl
Segmentation fault (core dumped)
[papa@arch-pc ~]$ coredumpctl gdb qjackctl

Results:
https://gist.github.com/passel/2e098b83 … 78ca5c8fa3

EDIT:
I don't know if it will help, but on a whim I also looked in dmesg, and found this:

[32223.954893] qjackctl[20183]: segfault at 0 ip 00007ff24e890071 sp 00007ffeb0d0a460 error 4 in libjack.so.0.1.0[7ff24e890000+1c000]
[32223.954905] Code: 00 0f 0b 0f b6 04 25 31 00 00 00 0f 0b 48 8b 04 25 00 00 00 00 0f 0b 48 8b 04 25 00 00 00 00 0f 0b 8b 04 25 18 62 45 02 0f 0b <48> 8b 04 25 00 00 00 00 0f 0b 90 48 8b bd 60 ff ff ff 48 39 df 75
[32223.954936] audit: type=1701 audit(1642415509.135:224): auid=1000 uid=1000 gid=1000 ses=2 pid=20183 comm="qjackctl" exe="/usr/bin/qjackctl" sig=11 res=1

Last edited by edvard (2022-01-17 10:37:58)

qu@rk · 2022-01-18 08:49:47

Latest JACK update removed jack_load for me. Can't load netmanager anymore.

qu@rk · 2022-01-18 09:29:03

this update: https://github.com/archlinux/svntogit-p … 71875ca422
changed the build options for the jack2 package.
I just compiled the jack2 package with ./waf configure no other options and jack_load is back now.

edvard · 2022-01-20 01:54:50

OK, so it wasn't just me? Last night I did a build from source, and it was successfu; Qjackctl connects to the running jackd instance, and jack_control changes parameters. The previous one didn't.

EDIT: I just did a sync and update, and it looks like the changes hit the repos. Everything launches and works just fine. Nice!

Last edited by edvard (2022-01-20 01:55:22)

Arch Linux

#1 2022-01-17 06:19:32

[SOLVED] Jack2 not working after update

#2 2022-01-17 07:52:01

Re: [SOLVED] Jack2 not working after update

#3 2022-01-17 10:34:04

Re: [SOLVED] Jack2 not working after update

#4 2022-01-18 08:49:47

Re: [SOLVED] Jack2 not working after update

#5 2022-01-18 09:29:03

Re: [SOLVED] Jack2 not working after update

#6 2022-01-20 01:54:50

Re: [SOLVED] Jack2 not working after update

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