$ charm build -l DEBUG
build: Composing into /home/jrwren/src/charms
build: {
  "INTERFACE_PATH": "/home/jrwren/src/charms/interfaces",
  "JUJU_REPOSITORY": "/home/jrwren/src/charms",
  "LAYER_PATH": "/home/jrwren/src/charms/layers",
  "_charm": ".",
  "_name": "parse-server",
  "config": "BuildConfig({'_tactics': [], 'configured': False})",
  "deps": "/home/jrwren/src/charms/deps",
  "force": false,
  "hide_metrics": false,
  "interface_service": "http://interfaces.juju.solutions",
  "log_level": "DEBUG",
  "output_dir": "/home/jrwren/src/charms",
  "repo": "/home/jrwren/src/charms/trusty",
  "series": "trusty",
  "target_dir": "/home/jrwren/src/charms/trusty/parse-server"
}
build: Unable to locate layer:nodejs. Do you need to set LAYER_PATH?