I think I just encountered the same bug today. I got stuck at some completely irrelevant kernel message in the boot screen. Couldn't switch to TTY, nada. I worked around it by adding
> modprobe.blacklist=amdgpu To the kernel parameters in grub. But the graphical installer still didn't work because the resolution wasn't right, so I also had to add > vga=792 Now, I can see the installer. I hope this resolves the issue for you, too. I also think that these kernel parameters should be included by default, because 1) amdgpu does not work without binary blobs AFAIK, so it can just be blacklisted 2) vga=792 corresponds to 1024×768x24, which is supported by pretty much any screen I've ever encountered. I'm not sure what happens when the screen doesn't support the resolution specified in the vga kernel parameter, but I think it just falls back to the standard, so it shouldn't do any harm
