get_platform_display is NULL

[kvark]

I'm looking at https://github.com/gfx-rs/wgpu-rs/issues/898#issuecomment-832960682 right now. None of the arguments are NULL, and there is 0x0000000000000000 as the top of the call stack, so it must be jumping the function pointer being NULL. At the same time, we are dealing with egl.upcast::<egl::EGL1_5>() result - should it not guarantee that get_platform_display is valid?

See our code at https://github.com/gfx-rs/gfx/blob/f43b7df0b6d596f51994d412ad862467ccba0e6b/src/backend/gl/src/window/egl.rs#L295

[timothee-haudebourg]

There is definitely something wrong here... egl.upcast::<egl::EGL1_5>() checks that the loaded version is at least EGL1_5, which is detected during the load_required call by checking that every EGL 1.5 symbols are provided by the library. I also check that the function pointer returned by libloading is not null to be extra sure.

I haven't been able to reproduce the issue, the upcast function seems to be working fine on my side.