I just tried to install this tool but got a series of errors from the npm installer. Here's the first part: > node-pre-gyp ERR! Tried to download(403): https://mapbox-node-binary.s3.amazonaws.com/mapnik/v3.6.2/node-v59-darwin-x64-Release.tar.gz node-pre-gyp ERR! Pre-built binaries not found for mapnik@3.6.2 and node@9.3.0 (node-v59 ABI) (falling back to source compile with node-gyp) AFAICT, the rest are consequences of failure to install mapnik.