4

I am using

  • Ubuntu 23.10
  • Slack 4.35.121
  • Pipewire 0.3.79-2
  • amdgpu

Issue

Both Slack installations show black screen when sharing:

  1. Snap version of Slack with (or without) slack --enablefeatures=WebRTCPipeWireCapturer
  2. Deb version of Slack slack-desktop-4.34.121-amd64

Previously I had Fedora 37 on 6.12 kernel gnome 43 and Slack was able to share screen, so it's definitely possible.

What works

  1. Screen sharing works on Xorg
  2. Screen sharing works on Chromium based browser (Brave)

Diagnostics

Display server

$ echo $XDG_SESSION_TYPE                        
wayland
### Graphics device
```sh
$ sudo lspci -k | grep -EA3 'VGA|3D|Display'
pcilib: Error reading /sys/bus/pci/devices/0000:00:08.3/label: Operation not permitted
03:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Navi 23 [Radeon RX 6650 XT / 6700S / 6800S] (rev c0)
        Subsystem: ASUSTeK Computer Inc. Navi 23 [Radeon RX 6650 XT]
        Kernel driver in use: amdgpu
        Kernel modules: amdgpu
--
07:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Rembrandt [Radeon 680M] (rev c7)
        Subsystem: ASUSTeK Computer Inc. Rembrandt [Radeon 680M]
        Kernel driver in use: amdgpu
        Kernel modules: amdgpu

Pipewire versions

$ dpkg -l | grep -i pipewire                                 
ii  gnome-remote-desktop                             45.0-1                                    amd64        Remote desktop daemon for GNOME using PipeWire
ii  gstreamer1.0-pipewire:amd64                      0.3.79-2                                  amd64        GStreamer 1.0 plugin for the PipeWire multimedia server
ii  libpipewire-0.3-0:amd64                          0.3.79-2                                  amd64        libraries for the PipeWire multimedia server
ii  libpipewire-0.3-common                           0.3.79-2                                  all          libraries for the PipeWire multimedia server - common files
ii  libpipewire-0.3-modules:amd64                    0.3.79-2                                  amd64        libraries for the PipeWire multimedia server - modules
ii  libspa-0.2-bluetooth:amd64                       0.3.79-2                                  amd64        libraries for the PipeWire multimedia server - bluetooth plugins
ii  libspa-0.2-modules:amd64                         0.3.79-2                                  amd64        libraries for the PipeWire multimedia server Simple Plugin API - modules
ii  pipewire:amd64                                   0.3.79-2                                  amd64        audio and video processing engine multimedia server
ii  pipewire-alsa:amd64                              0.3.79-2                                  amd64        PipeWire ALSA plugin
ii  pipewire-audio                                   0.3.79-2                                  all          recommended set of PipeWire packages for a standard audio desktop use
ii  pipewire-bin                                     0.3.79-2                                  amd64        PipeWire multimedia server - programs
ii  pipewire-pulse                                   0.3.79-2                                  amd64        PipeWire PulseAudio daemon
ii  wireplumber

Logs

I got following in the logs I see that there are some subprocesses with flag of disabled WebRTCPipeWireCapturer

user+   26075  7.3  0.5 1178928616 180012 ?   SLl  11:27   0:02 /snap/slack/110/usr/lib/slack/slack --no-sandbox --enable-features=WebRTCPipeWireCapturer --executed-from=/home/user --pid=25496
user+   26082  0.0  0.1 33988524 49408 ?      S    11:27   0:00 /snap/slack/110/usr/lib/slack/slack --type=zygote --no-zygote-sandbox --no-sandbox
user+   26083  0.0  0.1 33988520 49280 ?      S    11:27   0:00 /snap/slack/110/usr/lib/slack/slack --type=zygote --no-sandbox
user+   26099  0.0  0.0 33588712 3200 ?       Sl   11:27   0:00 /snap/slack/110/usr/lib/slack/chrome_crashpad_handler --monitor-self-annotation=ptype=crashpad-handler --no-upload-gzip --database=/home/user/snap/slack/110/.config/Slack/Crashpad --url=https://slack.com/apps/sentryproxy/api/5277886/minidump/?sentry_key=fd30fe469dbf4aec9db40548e5acf91e --annotation=_productName=Slack --annotation=_version=4.35.121 --annotation=lsb-release=Ubuntu Core 18 --annotation=plat=Linux --annotation=prod=Electron --annotation=sentry___initialScope={"release":"Slack@4.35.121","environment":"production","user":{"id":"e1f78694-1d56-4017-a027-beab0ea663ae"},"tags":{"uuid":"e1f78694-1d56-4017-a027-beab0ea663ae"}} --annotation=ver=27.0.0 --initial-client-fd=43 --shared-client-connection
user+   26126  2.2  0.2 34046980 72972 ?      Sl   11:27   0:00 /snap/slack/110/usr/lib/slack/slack --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=none --no-sandbox --enable-logging --crashpad-handler-pid=26099 --enable-crash-reporter=f0b3e071-ce2a-4a61-89db-a168791729e9,no_channel --user-data-dir=/home/user/snap/slack/110/.config/Slack --standard-schemes=app,slack-webapp-dev --secure-schemes=app,slack-webapp-dev --bypasscsp-schemes=slack-webapp-dev --cors-schemes=slack-webapp-dev --fetch-schemes=slack-webapp-dev --service-worker-schemes=slack-webapp-dev --streaming-schemes --enable-logging --log-file=/home/user/snap/slack/110/.config/Slack/logs/default/electron_debug.log --shared-files=v8_context_snapshot_data:100 --field-trial-handle=0,i,8702521800839048508,11262088157928811340,262144 --disable-features=AllowAggressiveThrottlingWithWebSocket,CalculateNativeWinOcclusion,HardwareMediaKeyHandling,IntensiveWakeUpThrottling,LogJsConsoleMessages,RequestInitiatorSiteLockEnfocement,SpareRendererForSitePerProcess,WebRTCPipeWireCapturer,WebRtcHideLocalIpsWithMdns,WinRetrieveSuggestionsOnlyOnDemand
user+   26179 37.9  1.3 1191407300 418572 ?   Sl   11:27   0:11 /snap/slack/110/usr/lib/slack/slack --type=renderer --crashpad-handler-pid=26099 --enable-crash-reporter=f0b3e071-ce2a-4a61-89db-a168791729e9,no_channel --user-data-dir=/home/user/snap/slack/110/.config/Slack --standard-schemes=app,slack-webapp-dev --secure-schemes=app,slack-webapp-dev --bypasscsp-schemes=slack-webapp-dev --cors-schemes=slack-webapp-dev --fetch-schemes=slack-webapp-dev --service-worker-schemes=slack-webapp-dev --streaming-schemes --app-path=/snap/slack/110/usr/lib/slack/resources/app.asar --enable-sandbox --enable-blink-features=ExperimentalJSProfiler --disable-blink-features --first-renderer-process --no-sandbox --autoplay-policy=no-user-gesture-required --enable-logging --force-color-profile=srgb --log-file=/home/user/snap/slack/110/.config/Slack/logs/default/electron_debug.log --lang=en-US --num-raster-threads=4 --enable-main-frame-before-activation --renderer-client-id=4 --time-ticks-at-unix-epoch=-1698307092377958 --launch-time-ticks=5365682318 --shared-files=v8_context_snapshot_data:100 --field-trial-handle=0,i,8702521800839048508,11262088157928811340,262144 --disable-features=AllowAggressiveThrottlingWithWebSocket,CalculateNativeWinOcclusion,HardwareMediaKeyHandling,IntensiveWakeUpThrottling,LogJsConsoleMessages,RequestInitiatorSiteLockEnfocement,SpareRendererForSitePerProcess,WebRTCPipeWireCapturer,WebRtcHideLocalIpsWithMdns,WinRetrieveSuggestionsOnlyOnDemand --window-type=main
user+   26229  7.5  0.3 34636732 127500 ?     Sl   11:27   0:02 /snap/slack/110/usr/lib/slack/slack --type=gpu-process --no-sandbox --enable-logging --crashpad-handler-pid=26099 --enable-crash-reporter=f0b3e071-ce2a-4a61-89db-a168791729e9,no_channel --user-data-dir=/home/user/snap/slack/110/.config/Slack --gpu-preferences=WAAAAAAAAAAgAAAEAAAAAAAAAAAAAAAAAABgAAAAAAA4AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABAAAAGAAAAAAAAAAYAAAAAAAAAAgAAAAAAAAACAAAAAAAAAAIAAAAAAAAAA== --use-gl=angle --use-angle=swiftshader-webgl --enable-logging --log-file=/home/user/snap/slack/110/.config/Slack/logs/default/electron_debug.log --shared-files --field-trial-handle=0,i,8702521800839048508,11262088157928811340,262144 --disable-features=AllowAggressiveThrottlingWithWebSocket,CalculateNativeWinOcclusion,HardwareMediaKeyHandling,IntensiveWakeUpThrottling,LogJsConsoleMessages,RequestInitiatorSiteLockEnfocement,SpareRendererForSitePerProcess,WebRTCPipeWireCapturer,WebRtcHideLocalIpsWithMdns,WinRetrieveSuggestionsOnlyOnDemand
user+   26318  5.7  0.2 34227536 64128 ?      Sl   11:27   0:01 /snap/slack/110/usr/lib/slack/slack --type=utility --utility-sub-type=audio.mojom.AudioService --lang=en-US --service-sandbox-type=none --no-sandbox --enable-logging --crashpad-handler-pid=26099 --enable-crash-reporter=f0b3e071-ce2a-4a61-89db-a168791729e9,no_channel --user-data-dir=/home/user/snap/slack/110/.config/Slack --standard-schemes=app,slack-webapp-dev --secure-schemes=app,slack-webapp-dev --bypasscsp-schemes=slack-webapp-dev --cors-schemes=slack-webapp-dev --fetch-schemes=slack-webapp-dev --service-worker-schemes=slack-webapp-dev --streaming-schemes --enable-logging --log-file=/home/user/snap/slack/110/.config/Slack/logs/default/electron_debug.log --shared-files=v8_context_snapshot_data:100 --field-trial-handle=0,i,8702521800839048508,11262088157928811340,262144 --disable-features=AllowAggressiveThrottlingWithWebSocket,CalculateNativeWinOcclusion,HardwareMediaKeyHandling,IntensiveWakeUpThrottling,LogJsConsoleMessages,RequestInitiatorSiteLockEnfocement,SpareRendererForSitePerProcess,WebRTCPipeWireCapturer,WebRtcHideLocalIpsWithMdns,WinRetrieveSuggestionsOnlyOnDemand
user+   26366  0.0  0.0  17784  2304 pts/0    S+   11:28   0:00 grep --color=auto --exclude-dir=.bzr --exclude-dir=CVS --exclude-dir=.git --exclude-dir=.hg --exclude-dir=.svn --exclude-dir=.idea --exclude-dir=.tox slack
hc_dev
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user2408334
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2 Answers2

10

The newer slacks explicitly disable WebRTCPipeWireCapturer, but you can get around that by editing the JS resource file directly. There's some integrity checking, and it needed to be the same length or Slack wouldn't start at all, but the following command worked for me on 4.35.121. Of course need to pass in the command line option --enable-features=WebRTCPipeWireCapturer as before and/or put it in a desktop file.

sudo sed -i'.backup' -e 's/,"WebRTCPipeWireCapturer"/,"LebRTCPipeWireCapturer"/' /usr/lib/slack/resources/app.asar

The desktop file can be in ~/.local/share/applications/slack.desktop and won't be clobbered by updates, but the app.asar patching needs to be repeated after each update.

dlandau
  • 101
2

According to a thread in Slack community forums the latest version with working screen sharing on Wayland was:

  • slack-desktop-4.29.149

How to use Slack's Debian package for screen sharing

One can download it , install and run it using following commands

# Download
wget https://downloads.slack-edge.com/releases/linux/4.29.149/prod/x64/slack-desktop-4.29.149-amd64.deb


install


sudo dpkg -i slack-desktop-4.29.149-amd64.deb


run and check whether screen sharing works


slack --enable-features=WebRTCPipeWireCapturer

Don't forget to update the .desktop file if it's working

nano /usr/share/applications/slack.desktop
hc_dev
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user2408334
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