Same problem here. Installing nvidia-kernel-dkms from unstable (455.23.04-1) works.
- Bug#972514: nvidia-kernel-dkms: fails to build with lin... Matthias Cramer
- Bug#972514: nvidia-kernel-dkms: fails to build wit... Wellington Almeida
- Bug#972514: nvidia-kernel-dkms: fails to build wit... Alexander Heinlein
- Bug#972514: nvidia-kernel-dkms: fails to build wit... Rob Oosterling
- Bug#972514: nvidia-kernel-dkms: fails to build wit... Heinz Repp
