Node 6 bug reduced reproduction

I've noticed a minor breaking change in either child_process.spawn or path.resolve (currently unclear), on Windows with Node 6. This issue appears to crop up when a Node file is execute from a SUBST path.

Summary

Executing a Node file on a "virtual" drive, which then spawn's a node child process with a file also on the "virtual" drive. The child process executes the file at it's "real" location.

This was not the case prior to Node 6.

This alone isn't a big problem. However when path.resolve is run in the child process the resolved path is on the virtual drive.

This becomes an issue when entry file of child process and the path.resolve'd file but require a native extension. This, as expected, causes Error: Module did not self-register..

Requirements

• Node 6
• Windows

To reproduce this locally

mkdir c:\projects
cd c:\projects
git clone https://github.com/xzyfer/node-6-native-ext-bug.git
cd node-6-native-ext-bug
subst s: c:\projects
npm install
npm test

Error

Error: Module did not self-register.
    at Error (native)
    at Object.Module._extensions..node (module.js:568:18)
    at Module.load (module.js:456:32)
    at tryModuleLoad (module.js:415:12)
    at Function.Module._load (module.js:407:3)
    at Module.require (module.js:466:17)
    at require (internal/module.js:20:19)
    at Object.<anonymous> (s:\node_modules\node-6-native-ext-bug\subloader.js:10:1)
    at Module._compile (module.js:541:32)
    at Object.Module._extensions..js (module.js:550:10)

Notes

I've chosen to use buffertools as native module for this reproduction because it's simple and maintained by a Node core developer.

You can see an example of this error in AppVeyor