[MU4 Issue] No sound on linux

I am trying MuseScore 4 on an uptodate Fedora 35 x86_64 linux machine. I have no sound at all:

• no sound when placing a note on the score
• no sound when trying to play the score.
  Furthermore, when a score is played, the notes being played are supposed to be highlighted, and the highlighting is supposed to be moving through the score. With MuseScore 4, there is no sound, the first note is highlighted, and the highlighting isn't moving: it remains on the first note that should have been played.

This behaviour occurs with the pre-alpha built, and the latest nightly:

• MuseScore-4.0.0.2059995262-x86_64.AppImage
• MuseScoreNightly-202204160416-master-8b45a35-x86_64.AppImage

Playback works correctly with MuseScore 3, both the version packaged with fedora, and the latest nightly

• mscore-3.6.2-5.fc35.x86_64
• MuseScoreNightly-202204160418-3.x-2513676-x86_64.AppImage

In the rest of this bug report, I copy the log of the pre-alpha built while commenting what I do.

** I start with a clean state:
** % rm -rf ~/.config/MuseScore/MuseScore4.ini ~/.local/share/MuseScore/MuseScore4
** And launch Musescore:
** % ./MuseScore-4.0.0.2059995262-x86_64.AppImage

/usr/lib64/pipewire-0.3/jack/libjack.so.0
/lib64/libnss3.so
QEventLoop: Cannot be used without QApplication
QEventLoop: Cannot be used without QApplication
12:09:01.317 | INFO | main_thread | GlobalModule | onInit: log path: /home/eric/.local/share/MuseScore/MuseScore4/logs/MuseScore_220417_120901.log
12:09:01.317 | INFO | main_thread | GlobalModule | onInit: === Started MuseScore 4.0.0, build number 2059995262 ===
12:09:01.409 | INFO | main_thread | DiagnosticsModule | onInit: success start crash handler
12:09:01.580 | WARN | main_thread | Qt | QIODevice::read (QFile, "/home/eric/.local/share/MuseScore/MuseScore4/shortcuts.xml"): device not open
12:09:01.580 | WARN | main_thread | Qt | QIODevice::read (QFile, "/home/eric/.local/share/MuseScore/MuseScore4/midi_mappings.xml"): device not open
12:09:02.163 | ERROR | main_thread | WorkspaceManager | findWorkspaceFiles: [401] The file does not exist
12:09:02.163 | WARN | main_thread | WorkspaceManager | setupDefaultWorkspace: not found default workspace, will be created new
12:09:02.164 | ERROR | main_thread | PluginsConfiguration | updatePluginsConfiguration: [401] The file does not exist
12:09:02.293 | WARN | main_thread | IpcSocket | connect: failed connect to server
12:09:02.293 | WARN | main_thread | IpcSocket | connect: failed connect to server
12:09:02.294 | ERROR | main_thread | IpcServer | listen: failed listen: "QLocalServer::listen: Address in use"
12:09:02.294 | WARN | main_thread | IpcSocket | connect: failed connect to server
12:09:03.754 | ERROR | main_thread | AppShellConfiguration | sessionProjectsPaths: [401] The file does not exist
12:09:04.927 | ERROR | 139816989603392 | LanguagesConfiguration | languages: [401] The file does not exist
12:09:04.930 | WARN | 139816989603392 | Qt | QObject::connect: Cannot queue arguments of type 'QLocalSocket::LocalSocketError'
(Make sure 'QLocalSocket::LocalSocketError' is registered using qRegisterMetaType().)
12:09:04.931 | WARN | 139816989603392 | IpcSocket | connect: failed connect to server
12:09:04.931 | WARN | 139816989603392 | IpcSocket | connect: failed connect to server
12:09:04.931 | ERROR | 139816989603392 | IpcServer | listen: failed listen: "QLocalServer::listen: Address in use"
12:09:04.931 | WARN | 139816989603392 | IpcSocket | connect: failed connect to server
12:09:04.931 | WARN | 139816989603392 | Qt | QIODevice::write (QLocalSocket): device not open
12:09:04.931 | WARN | 139816989603392 | Qt | QAbstractSocket::waitForBytesWritten() is not allowed in UnconnectedState
12:09:04.932 | ERROR | 139816989603392 | ipc | writeToSocket: failed write to socket, err: "QLocalSocket::connectToServer: Socket access error"
**
** At this points, there are two open windows: the greyed-out main musescore window, and a small
** "Getting started", "Welcome to Musescore 4" window. Furthermore, in the audio volume applet, I see
** an audio playing app registered as "ALSA-plug-in [mscore-portable]". (Side note: fedora uses
** pulseaudio, but this is supposed to be compatible with ALSA.)
** I checked, of course, that this is not muted and that volume is at 100%.
**
** I now click on "Next" in the "Getting started" windows to select the "light" theme. The "Getting started"
** windows asks me about playback. There is a large "Placeholder" image, and it suggests me to download
** the" Muse symphony Orchestra library". However, the download button does nothing at all (no effect, no new
** log line). Is this a bug? Is it supposed to work yet? I don't know and I click on "Next".
**
** The last part of getting started informs me of video tutorial. I click on "Finish". New log lines;
**
12:17:24.546 | WARN | main_thread | IpcSocket | connect: failed connect to server
12:17:24.546 | WARN | main_thread | IpcSocket | connect: failed connect to server
12:17:24.547 | ERROR | main_thread | IpcServer | listen: failed listen: "QLocalServer::listen: Address in use"
12:17:24.547 | WARN | main_thread | IpcSocket | connect: failed connect to server
12:17:24.547 | WARN | main_thread | Qt | QIODevice::write (QLocalSocket): device not open
12:17:24.547 | WARN | main_thread | Qt | QAbstractSocket::waitForBytesWritten() is not allowed in UnconnectedState
12:17:24.547 | ERROR | main_thread | ipc | writeToSocket: failed write to socket, err: "QLocalSocket::connectToServer: Socket access error"
12:17:24.547 | WARN | main_thread | IpcSocket | connect: failed connect to server
12:17:24.548 | WARN | main_thread | IpcSocket | connect: failed connect to server
12:17:24.548 | ERROR | main_thread | IpcServer | listen: failed listen: "QLocalServer::listen: Address in use"
12:17:24.548 | WARN | main_thread | IpcSocket | connect: failed connect to server
12:17:24.548 | WARN | main_thread | Qt | QIODevice::write (QLocalSocket): device not open
12:17:24.548 | WARN | main_thread | Qt | QAbstractSocket::waitForBytesWritten() is not allowed in UnconnectedState
12:17:24.548 | ERROR | main_thread | ipc | writeToSocket: failed write to socket, err: "QLocalSocket::connectToServer: Socket access error"
12:17:24.549 | WARN | main_thread | IpcSocket | connect: failed connect to server
12:17:24.549 | WARN | main_thread | IpcSocket | connect: failed connect to server
12:17:24.549 | ERROR | main_thread | IpcServer | listen: failed listen: "QLocalServer::listen: Address in use"
12:17:24.549 | WARN | main_thread | IpcSocket | connect: failed connect to server
12:17:24.549 | WARN | main_thread | Qt | QIODevice::write (QLocalSocket): device not open
12:17:24.550 | WARN | main_thread | Qt | QAbstractSocket::waitForBytesWritten() is not allowed in UnconnectedState
12:17:24.550 | ERROR | main_thread | ipc | writeToSocket: failed write to socket, err: "QLocalSocket::connectToServer: Socket access error"

** In the main musescore window, I click "Scores", then "New". The "New Score" window appears and:

12:18:29.492 | INFO | main_thread | ActionsDispatcher | dispatch: try call action: file-new
12:18:29.619 | ERROR | main_thread | AppShell | run: error: qrc:/qml/MuseScore/Project/internal/KeySignatureSettings.qml:118:13: QML KeySignatureListView: Binding loop detected for property "rows"
12:18:29.620 | WARN | main_thread | Qt | qrc:/qml/MuseScore/Project/internal/KeySignatureSettings.qml:118:13: QML KeySignatureListView: Binding loop detected for property "rows"

** I choose to put a Violin (I have tried other instruments in other sessions), and click "Done". The main window is
** active with the new score.

12:20:29.314 | ERROR | main_thread | AppShellConfiguration | sessionProjectsPaths: [401] The file does not exist
12:20:29.315 | WARN | main_thread | IpcSocket | connect: failed connect to server
12:20:29.315 | WARN | main_thread | IpcSocket | connect: failed connect to server
12:20:29.315 | ERROR | main_thread | IpcServer | listen: failed listen: "QLocalServer::listen: Address in use"
12:20:29.315 | WARN | main_thread | IpcSocket | connect: failed connect to server
12:20:29.315 | WARN | main_thread | Qt | QIODevice::write (QLocalSocket): device not open
12:20:29.316 | WARN | main_thread | Qt | QAbstractSocket::waitForBytesWritten() is not allowed in UnconnectedState
12:20:29.316 | ERROR | main_thread | ipc | writeToSocket: failed write to socket, err: "QLocalSocket::connectToServer: Socket access error"
12:20:29.379 | WARN | main_thread | IpcSocket | connect: failed connect to server
12:20:29.380 | WARN | main_thread | IpcSocket | connect: failed connect to server
12:20:29.380 | ERROR | main_thread | IpcServer | listen: failed listen: "QLocalServer::listen: Address in use"
12:20:29.380 | WARN | main_thread | IpcSocket | connect: failed connect to server
12:20:29.380 | WARN | main_thread | Qt | QIODevice::write (QLocalSocket): device not open
12:20:29.380 | WARN | main_thread | Qt | QAbstractSocket::waitForBytesWritten() is not allowed in UnconnectedState
12:20:29.380 | ERROR | main_thread | ipc | writeToSocket: failed write to socket, err: "QLocalSocket::connectToServer: Socket access error"
12:20:29.662 | ERROR | 139818259252800 | SynthResolver | resolveSynth: invalid audio source params for trackId: 0
12:20:29.798 | INFO | 139818259252800 | FluidSynth | addSoundFonts: success load soundfont: /tmp/.mount_MuseScKeTjRu/share/mscore-portable-4.0/sound/MuseScore_General.sf3
12:20:35.901 | ERROR | 139818259252800 | SynthResolver | resolveSynth: invalid audio source params for trackId: 1
12:20:36.016 | INFO | 139818259252800 | FluidSynth | addSoundFonts: success load soundfont: /tmp/.mount_MuseScKeTjRu/share/mscore-portable-4.0/sound/MuseScore_General.sf3

** I click the little pencil to enter new notes

12:21:31.090 | INFO | main_thread | ActionsDispatcher | dispatch: try call action: note-input-steptime

** and enter four notes. I have a line of log for each note. No sound at all.

12:22:11.216 | INFO | main_thread | ActionsDispatcher | dispatch: try call action: put-note
12:22:12.653 | INFO | main_thread | ActionsDispatcher | dispatch: try call action: put-note
12:22:14.654 | INFO | main_thread | ActionsDispatcher | dispatch: try call action: put-note
12:22:16.170 | INFO | main_thread | ActionsDispatcher | dispatch: try call action: put-note

** I click The Play button (small triangle) in the toolbar. The last note gets highlighted, no sound, and:

12:23:39.756 | INFO | main_thread | ActionsDispatcher | dispatch: try call action: play

** I click the pause button

12:23:44.153 | INFO | main_thread | ActionsDispatcher | dispatch: try call action: play

** I click the "Rewind" button

12:24:44.901 | INFO | main_thread | ActionsDispatcher | dispatch: try call action: rewind

** and the play button again. The first note gets highlighted, there is no sound, the highlighting does not move and again the same line in the log.

12:25:15.816 | INFO | main_thread | ActionsDispatcher | dispatch: try call action: play

** etc...