Comment 6 for bug 1638463

Thank you for taking the time to report this bug and helping to make Ubuntu better.

As per the Debian changelog entry below this has been fixed in the upstream Debian packaging. And since Ubuntu package version 1:1.0.0.61-2ubuntu1 (Ubuntu 20.04) those changes have been present in the Ubuntu packaging as well. Therefore I am marking this bug as fixed released.

"steam (1.0.0.59-3) unstable; urgency=medium

  * Add Conflicts/Replaces on steam-launcher.
    steam-launcher is a Valve-provided package containing the same
    launcher as Debian's steam package, and the same udev rules as
    Debian's steam-devices package. They are not co-installable: please
    install the steam and steam-devices packages from Debian non-free,
    *or* the steam and steam-launcher packages from Valve, but do not
    mix the two sources.
..."