The Kipon electronic adapter for Canon EOS to Fujifilm GFX is now available for pre-order at Adorama here.
“Kipon EF-GFX E adapter is designed for the Fuji GFX Medium Format camera, allowing Canon EOS mount lenses to be mounted onto Fuji GFX Medium Format camera bodies. This adapter features you can control the lens aperture electronically with the adapter itself
With KIPON EF-GFX E adapter, although the lens will fit physically, auto-focusing, and other functions will not work, only manual model will be available.”
Kipon offers many more adapters. Full overview in this fujirumors article.