What I Wanted to Do
Install a local dependency (…/something) that depends on another local dependency.
What Happened Instead
It works as long as there is no package-lock file, but once the package-lock file is there it will get confused about where the dependency of the dependency is.
Here is a minimal repository showing the error in practice https://github.com/afreakk/npm-error-example
npm version 6.9.0