I found this bug while using os.tmpdir()

When executing as root on OSX, there is no explicit tmpdir provided from the environment variables. When using os.tmpdir(), node correctly falls back to '/tmp'. However when running scripts via npm, it seems that the environment variable TMPDIR is set to the cwd when undefined. This causes os.tmpdir() to incorrectly return the cwd as the tmp directory.

in my package.json

"scripts": {
    "test": "echo $TMPDIR"
  },

npm test
#=> correct temp dir
sudo npm test
#=> current working directory (??)
node -e "console.log(process.env.TMPDIR)"
#=> correct temp dir
sudo node -e "console.log(process.env.TMPDIR)"
#=> undefined

another test, in my package.json

"scripts": {
    "test": "node -e \"console.log(require('os').tmpdir())\""
  },

npm test
#=> correct temp dir
sudo npm test
#=> current working directory (??)
node -e "console.log(require('os').tmpdir())"
#=> correct temp dir
sudo node -e "console.log(require('os').tmpdir())"
#=> '/tmp'

my system (osx 10.9.1):

node -v
#=> v0.10.22
npm -v
#=> 1.3.14