* installing *source* package ‘rgrpc’ ...
** this is package ‘rgrpc’ version ‘0.1.1’
** package ‘rgrpc’ successfully unpacked and MD5 sums checked
** using staged installation
ERROR: pkg-config cannot find 'grpc++'.
  Ubuntu/Debian: sudo apt install libgrpc++-dev libprotobuf-dev
  (libgrpc++-dev, not libgrpc-dev: the C-only package leaves
   the C++ runtime and grpc++.pc missing. libgrpc++-dev does
   not pull libprotobuf-dev under --no-install-recommends.)
ERROR: configuration failed for package ‘rgrpc’
* removing ‘/Volumes/Builds/packages/big-sur-x86_64/results/4.5/rgrpc.Rcheck/rgrpc’