How to set environment variables to get forever run meteorjs

How do you set the environment variables to get forever run meteorjs? If I do an export and run forever, like so

export PORT=80 MONGO_URL=mongodb://localhost:3002/appname

sudo forever -f start bundle/main.js

forever will not run the meteorjs bundle with node:

/Users/../bundle/server/server.js:166
throw new Error("MONGO_URL must be set in environment");
      ^
Error: MONGO_URL must be set in environment
at run (/Users/../bundle/server/server.js:166:11)
at Object.<anonymous> (/Users/../bundle/server/server.js:331:1)
at Module._compile (module.js:456:26)
at Object.Module._extensions..js (module.js:474:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Module.require (module.js:364:17)
at require (module.js:380:17)
at Object.<anonymous> (/Users/../bundle/main.js:1:63)
at Module._compile (module.js:456:26)
error: Forever detected script exited with code: 8

If I run it directly, it runs smoothly:

sudo PORT=80 MONGO_URL=mongodb://localhost:3002/appname ROOT_URL=http://myapp.com node bundle/main.js

If I do it like in this answer it works. But why doesn't it work with the export statement? Is there a way to tell forever a config file to read those settings? I don't see a way in the forever docs.