Trying to create a global npm module. When executing my command I get "The system cannot find the path specified"

I'm trying to convert a npm module I created to be used globally. https://github.com/toymachiner62/node-mongo-seeds/tree/global

When I run $ seed, it gives the error The system cannot find the path specified so it knows that it's a global command.

I'm not sure where to start debugging this. I have console.logs in all my scripts and none of them are firing so the problem lies elsewhere, but i'm not sure what to try next.

Advice?

edit

I'm now on my mac and I changed the shebang path to node in seed to #!/usr/local/bin node.

I still get these errors when trying to use my module:

$ seed
-bash: /usr/local/bin/seed: /usr/local/bin: bad interpreter: Permission denied
$ sudo seed
sudo: unable to execute /usr/local/bin/seed: Permission denied

edit

It seems this is only an issue on one of my macs. The other one works just fine..