Difference between where node_modules are stored in build

I am currently debugging a package and to do so I am looking through the output of the build, since allegedly node_modules/webpack is missing.

Upon inspection webpack is within node modules but nested under npm/node_modules/webpack.

My question is, what are the differences that cause meteor to either store node modules in either:


This is not causing an error on dev, only test.

Perhaps the answer to this will help with my debugging.