Project with a linked module fails with "Module not found" about npm-install HOT 1 CLOSED

More context from the Slack thread:

I've been able to reproduce the issue and I think I see what the problem is. We aren't really supporting workspaces with what we are doing with the node_modules layer and the symlink indirection. Let me explain.

When you npm install and reference workspaces, the package-lock.json just includes some file path references to where those workspaces are relative to the package-lock.json file. This is fine as long as the node_modules directory stays put. However, in order to make layer caching work well, we are moving the node_modules directory to /layers/paketo-buildpacks_npm-install/build-modules/node_modules and then doing some symlink redirection to make this work. Unfortunately, those file path references in the package-lock.json file are now broken since they were relative to the original location of the node_modules directory.

The solution to this is likely to add more explicit support for workspaces into the npm-install buildpack so that these workspace packages move along with the node_modules directory and their paths don't get messed up.

from npm-install.