Comment 8 for bug 1863255

So ibus was recently updated in focal and this moves the ibus socket path from /tmp to the users home directory - the existing desktop_legacy interface species the ibus socket path in /tmp still:

# allow communicating with ibus-daemon (this allows sniffing key events)
unix (connect, receive, send)
    type=stream
    peer=(addr="@/tmp/ibus/dbus-*"),

So this needs to have something like the following added:

unix (connect, receive, send)
     type=stream
     peer=(addr="@/home/*/.cache/ibus/dbus-*"),

to the desktop-legacy interface (OR ibus is reverted to move the socket back to /tmp however from a security point-of-view I think it is better to have the ibus socket address in the user's home directory).

I don't think there is a way to use the @{HOME} variable in this rule hence the /home/*/ above