Wayland availability detection does not check for WAYLAND_SOCKET

[mstoeckl]

Wayland clients have two methods of connecting to the compositor. If the environment variable WAYLAND_DISPLAY is set, they can connect() to the Unix socket at a path indicated by WAYLAND_DISPLAY. A much rarer case is when the environment variable WAYLAND_SOCKET is set; then the compositor will have provided one end of a socket pair through file descriptor inheritance, and the value of WAYLAND_SOCKET will indicate the file descriptor ID.

Currently, winit when autodetecting which backend to use only checks for WAYLAND_DISPLAY, not WAYLAND_SOCKET. (The code that does this check is in src/platform_impl/linux/mod.rs .) It should consider the Wayland backend to be usable if either of WAYLAND_DISPLAY or WAYLAND_SOCKET is available.

To test this, run a program using winit under a compositor or tool that provides a Wayland connection using WAYLAND_SOCKET. (The way I ran into this issue was with the command waypipe--oneshot ssh localhostalacritty.)

[kchibisov]

#3460

[kchibisov]

I have a feeling that if you set WAYLAND_DISPLAY to some garbage value it'll workaround the issue.

[kchibisov]

While I was testing it, I've discovered that empty WAYLAND_SOCKET prevents from running as will if you have e.g. WAYLAND_DISPLAY set Smithay/wayland-rs#697

The logic in wayland-rs follows the libwayland here, hence do you happen to know why it's like that there?

[kchibisov]

opened upstream https://gitlab.freedesktop.org/wayland/wayland/-/issues/438