How to interact with Gallium interface to support Zink Kopper?

I am implementing Haiku EGL driver over Gallium loaded by Glvnd [1]. It 
is already working with Llvmpipe, but it crashes with Zink Kopper in 
[2]. I think I am doing something wrong in eglSwapBuffers implementation 
[3]. Any ideas?

Note that Haiku Kopper Vulkan surface support code is not published yet, 
but it should be not a problem.

1. https://github.com/X547/mesa
2. 
https://github.com/X547/mesa/blob/1e90e3325b27588f2de4c1bf7e1cbaacb818253b/src/gallium/drivers/zink/zink_kopper.c#L644
3. 
https://github.com/X547/mesa/blob/97fd9341add54ee1cf89b42287e5c06115af1ec0/src/egl/drivers/haiku/egl_haiku.cpp#L443