ERROR: cuvid requested, but not all dependencies are satisfied: cuda/ffnvcodec

I updated the cuda from 8.0 to 9.1
when I recompile the ffmpeg as before

./configure --disable-debug --enable-shared --enable-pic --enable-cuda --enable-cuvid --enable-nvenc --enable-nonfree --enable-libnpp --extra-cflags=-I/usr/local/cuda/include --extra-ldflags=-L/usr/local/cuda/lib64 --extra-libs=-ldl

Error came:

ERROR: cuvid requested, but not all dependencies are satisfied: cuda/ffnvcodec

I found this, it works
https://superuser.com/questions/1299064/error-cuvid-requested-but-not-all-dependencies-are-satisfied-cuda-ffnvcodec

Use

apt-get install pkgconf

this fixed it for me.