patch-slack

Rationale

The Slack desktop client for Linux has native support for using PipeWire to capture and share screen contents under Wayland. However, the WebRTCPipeWireCapturer option for its --enable-features CLI flag that enables the feature is apparently ignored on purpose in the current version. The following command patches the installed contents to forcefully re-enable the properly-implemented support:

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

taken from https://askubuntu.com/a/1492207.

Contents

The current project provides a very small Debian package that enables automatically running the above command on any DPKG installation or update that touches something under the /usr/lib/slack/resources directory of the slack-desktop package, using the DPKG trigger system. In itself, it does not contain anything, however.

Installation

• Audit the source files under debian/ to trust that nothing malicious will be attempted upon installing the package.
• Install the official devscripts package in order to gain access to the following two build dependencies.
• Clone the current repository anywhere you like and cd into it.
• Run debuild in order to build the package.
• Run sudo debi in order to install the just-built package.

Usage

The installed package does not provide anything to use per se, as it only performs a one-shot action from time to time. In order to check that it works, running grep 'WebRTCPipeWireCapturer' /usr/lib/slack/resources/app.asar should return a non-zero status and display nothing. Also, when (re)installing or updating slack-desktop, a line of the form Processing triggers for patch-slack ([version]) ... should appear at the end of APT's output. Finally, the Slack client should be restarted if running while the current package is installed.

Instructions on how to ensure the CLI option is always used when starting the client through the standard desktop API can be found at: https://www.guyrutenberg.com/2022/03/12/slack-screen-sharing-under-wayland/. You can also test things independently of Slack desktop along your way of setting up Wayland and PipeWire using another web browser by going to https://mozilla.github.io/webrtc-landing/gum_test.html.