npm link not working on Node 6

[jamestalmage]

To debug, I added the following statements to a number of internal AVA files:

console.log(__filename);

On Node 5, when everything works, I get this output:

/~/dev/ava/lib/fork.js
/~/dev/ava/lib/test-worker.js
/~/dev/ava/lib/test-worker.js
/~/dev/ava/lib/test-worker.js
/~/dev/ava/lib/test-worker.js
/~/dev/ava/index.js
/~/dev/ava/index.js
/~/dev/ava/index.js
/~/dev/ava/index.js
/~/dev/ava/index.js

On Node 6, where things are broken:

/~/dev/ava-codemods/node_modules/ava/lib/fork.js
/~/dev/ava/lib/test-worker.js
/~/dev/ava/lib/test-worker.js
/~/dev/ava/lib/test-worker.js
/~/dev/ava/lib/test-worker.js
/~/dev/ava-codemods/node_modules/ava/index.js
/~/dev/ava-codemods/node_modules/ava/index.js
/~/dev/ava-codemods/node_modules/ava/index.js
/~/dev/ava-codemods/node_modules/ava/index.js
/~/dev/ava-codemods/node_modules/ava/lib/test-worker.js
/~/dev/ava-codemods/node_modules/ava/lib/test-worker.js
/~/dev/ava-codemods/node_modules/ava/lib/test-worker.js
/~/dev/ava-codemods/node_modules/ava/index.js
/~/dev/ava-codemods/node_modules/ava/lib/test-worker.js

So, it appears that, in Node 6, npm linked modules think they are inside the node_modules folder of the project from which they are linked, instead of their actual path on the file system.

However, when we fork test-worker.js, it is aware of it's actual path. But that gets confused when when the user does require('ava') and the file paths show as nested again.

You will notice test-worker shows up twice as often as it should, with a deeper path the second time around.

[jamestalmage]

The new behavior is intentional: nodejs/node#5950

But problematic when calling fork.

[jamestalmage]

There is an open PR to revert the change: nodejs/node#6537