DMA-BUF screensharing crashes applications

• Fedora 34 Beta
• GNOME 40.0
• Pipewire 0.3.24
• Mesa 21.0.1
• amdgpu

If you enable the "dma-buf-screen-sharing" experimental feature, any program trying to screenshare (including the GNOME Shell screen recorder) crashes upon attempting to record the screen.

For example, xdg-screen-cast, produces the following error:

fish: Job 1, 'Desktop/xdp-screen-cast.py' terminated by signal SIGBUS (Misaligned address error)

Here's the core dump and the executable in case it's helpful:

core.xdp-screen-cast.1000.5bcbd6dc57db43f0987c5821a79a479f.3528.1617456016000000.zst python3