Carla fails to start engine on startup

[lgoette]

Hey there,
I got a weird problem where it fails to start the engine on the first startup after boot/login.

The system-logs say:

Jul 24 04:40:07 lamabus carla[17811]: Carla 2.5.8 started, status:
Jul 24 04:40:07 lamabus carla[17811]:   Python version: 3.11.9
Jul 24 04:40:07 lamabus carla[17811]:   Qt version:     5.15.14
Jul 24 04:40:07 lamabus carla[17811]:   PyQt version:   5.15.9
...
Jul 24 04:40:07 lamabus carla[17811]: [carla] Carla assertion failure: "fPatchbay != nullptr" in file CarlaEngineGraph.cpp, line 2787
Jul 24 04:40:07 lamabus carla[17811]: [carla] Carla assertion failure: "fPatchbay != nullptr" in file CarlaEngineGraph.cpp, line 2787
Jul 24 04:40:07 lamabus carla[17811]: [carla] Carla assertion failure: "fPatchbay != nullptr" in file CarlaEngineGraph.cpp, line 2787
Jul 24 04:40:07 lamabus carla[17811]: [carla] Carla assertion failure: "fPatchbay != nullptr" in file CarlaEngineGraph.cpp, line 2787
Jul 24 04:40:07 lamabus carla[17811]: [carla] carla_load_project: Engine is not initialized

And the carla-log says:
Failed to start engine on first try, ignored

I did not find anything like that in the Issues. Is this a known behavior? The carla-log message sounds like it.

[juanpc2018]

#1. IF Engine fails, probably its the Audio drivers...
for example:
if you are using Pulse Audio, at 48KHz,
does Not work,
because PulseAudio .config daemon file comes default to 44.1Khz forced,
does Not allow alternate sample rates, unless you manually configure PulseAudio .config file
see your settings:

$ cat /etc/pulse/daemon.conf

Kernel version? Kernel Type? OS type ?

#2. your startup is different, seems incomplete compiled.

here works ok:

$ carla
Carla 2.5.7 started, status:
  Python version: 3.10.12
  Qt version:     5.15.3
  PyQt version:   5.15.6
  Binary dir:     /usr/lib/carla
  Resources dir:  /usr/share/carla/resources
Frontend pixel ratio is 1.25
libjack.so.0 loaded successfully!
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock

$ ./carla
Carla 2.5.8 started, status:
  Python version: 3.10.12
  Qt version:     5.15.3
  PyQt version:   5.15.6
  Binary dir:     /media/me/XFS/Carla/Carla-2.5.8/bin
  Resources dir:  /media/me/XFS/Carla/Carla-2.5.8/bin/resources
Frontend pixel ratio is 1.25
libjack.so.0 loaded successfully!
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock

[juanpc2018]

Carla works best "easy" with qjackctl
or PulseAudio

ALSA complex

[lgoette]

Hey there,
thanks for the reply and sorry for the late reply from my side.
I am actually using Jack and not Pulse. And my Os is Nixos with a corresponding rt- kernel (6.6.30-rt30 64bit).

It seems to be a jack Issue. The jack log says:

Aug 07 14:27:32 lamabus jackd[942]: JackPosixProcessSync::LockedTimedWait error usec = 26660 err = Connection timed out
Aug 07 14:27:32 lamabus jackd[942]: JackEngine::ClientActivate wait error ref = 2 name = Carla
Aug 07 14:27:32 lamabus jackd[942]: JackPosixProcessSync::LockedTimedWait error usec = 26660 err = Connection timed out
Aug 07 14:27:32 lamabus jackd[942]: JackEngine::ClientDeactivate wait error ref = 2 name = Carla
Aug 07 14:27:32 lamabus jackd[942]: JackPosixProcessSync::LockedTimedWait error usec = 5332 err = Connection timed out
Aug 07 14:27:32 lamabus jackd[942]: JackEngine::ClientCloseAux wait error ref = 2

I found this jackaudio/jack2#441

I will try some thinks and get back if I find something :)