Following the instructions from the documentation. I create a new directory, and cd into it and run the command npm install --save mapbox-gl.
This results in the following error:

npm ERR! addLocal Could not install /Users/user/Sites/fallenleaves/node_modules/mapbox-gl/src/style-spec

It also made an npm-debug.log file. Let me know if a gist of this would be helpful.

I have never experienced this sort of error before with npm so I did some digging and couldn't find anything helpful. Not sure if this is to do with my setup, mapbox or npm. Any help appreciated.