Comment # 14 on bug 1141762 from Martin Li��ka

I can't reproduce it, I see following:

marxin@marxinbox:/tmp> zynaddsubfx

ZynAddSubFX - Copyright (c) 2002-2013 Nasca Octavian Paul and others
                Copyright (c) 2009-2019 Mark McCurry [active maintainer]
This program is free software (GNU GPL v2 or later) and 
it comes with ABSOLUTELY NO WARRANTY.

Try 'zynaddsubfx --help' for command-line options.

Sample Rate =         44100
Sound Buffer Size =     256 samples
Internal latency =     5.8 ms
ADsynth Oscil.Size =     1024 samples
lo server running on 15101
[INFO] Nio::start()
Starting Audio: JACK
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jackdmp 1.9.12
Copyright 2001-2005 Paul Davis and others.
Copyright 2004-2016 Grame.
Copyright 2016-2017 Filipe Coelho.
jackdmp comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details
Cannot create RT messagebuffer thread: Operation not permitted (1)
Retrying messagebuffer thread without RT scheduling
Messagebuffer not realtime; consider enabling RT scheduling for user
no message buffer overruns
Cannot create RT messagebuffer thread: Operation not permitted (1)
Retrying messagebuffer thread without RT scheduling
Messagebuffer not realtime; consider enabling RT scheduling for user
no message buffer overruns
Cannot create RT messagebuffer thread: Operation not permitted (1)
Retrying messagebuffer thread without RT scheduling
Messagebuffer not realtime; consider enabling RT scheduling for user
no message buffer overruns
JACK server starting in realtime mode with priority 10
self-connect-mode is "Don't restrict self connect requests"
Cannot lock down 86611866 byte memory area (Cannot allocate memory)
audio_reservation_init
Acquire audio card Audio0
creating alsa driver ... hw:0|hw:0|1024|2|48000|0|0|nomon|swmeter|-|32bit
ALSA: Cannot open PCM device alsa_pcm for playback. Falling back to
capture-only mode
JackTemporaryException : now quits...
Released audio card Audio0
audio_reservation_finish
Cannot initialize driver
JackServer::Open failed with -1
Failed to open server
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
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
Error, failed to open jack client on server:  status 17
Error, NULL jackClient through Start()
ERROR: The default audio output failed to open!
Starting MIDI: ALSA
MIDI Started
[INFO] exec-after-init
[INFO] startup OSC
[INFO] UI calbacks
[INFO] OSC replay
midi list updating...
[INFO] auto_save setup
[INFO] NSM Stuff
[INFO] LASH Stuff
[INFO] Main Loop...