process.env undefined in Node app

When running my Node app with node server.js, process.env returns undefined, so I'm unable to access any environment variables. This also seems to occur when I attempt to deploy my app to Duostack.

Calling process.env from the command line seems to work, though:

$ node
> process.env
{ MANPATH: '/opt/local/share/man:',
  TERM_PROGRAM: 'Apple_Termina开发者_运维技巧l',
...

Any idea what could be going wrong?

---

I figured it out. process is an object (https://nodejs.org/api/process.html), but I'd defined my own function (also called process) that overwrote it. Changing the name of my function fixed the problem.