Failed to initialize window when libwayland is not symllinked properly

[dsseng]

Description
GL backend does not work on Wayland.

Repro steps
0. wgpu repository

1. WGPU_BACKEND=gl cargo run --example cube panics
2. WAYLAND_DISPLAY= WGPU_BACKEND=gl cargo run --example cube works

Expected vs observed behavior
Expected: Both Wayland and X11 (Xwayland) work with both Vulkan and GLES
Got: Wayland only works with Vulkan, X11 is fine with both

Error: [2021-12-30T12:23:13Z ERROR wgpu_core::device] surface configuration failed: incompatible window kind

Extra materials
I'm going to investigate the issue on my own currently and submit a PR in case of successful fix.

Platform
GNOME Shell/Mutter 41.2 on Fedora 35
AMDGPU (Ryzen 4500U)
wgpu from master branch

[dsseng]

Resolved by looking for Wayland libraries in /lib64.
Instead of /lib64/libwayland-client.so I found /lib64/libwayland-client.so.0
Same for libwayland-egl: /lib64/libwayland-egl.so.1
When I added those version numbers into wgpu-hal/src/gles/egl.rs I got window with image working on my system, so it's packaging issue (maybe to be reported to Fedora maintainers).

It looks like we either should embed libwayland, use its Rust alternative or search for versioned libs: https://github.com/Smithay/wayland-rs/blob/ddd92dcaf6736c1822f7698cf0d8446f03773d36/wayland-sys/src/client.rs#L89

Btw there should at least be some graceful handling for case where we get X11 WSI and Wayland window here

[dsseng]

Internals of the issue:

1. Winit uses wayland-rs (as shown before, it's either able to find shared libraries or has Rust equivalent built-in)
2. Winit detects Wayland successfully and gives us a new Wayland window
3. wgpu-hal fails to find libraries for Wayland and switches over to X11
4. No way, we have X11 WSI and a Wayland window
   This could also be solved by falling back to creating different window so other bugs of such type (difference between Winit and wgpu-hal window types) won't lead to the same error