Here are all the environment variables Lulu seems to want to use.
BIND_ADDRESS
BOXEN_REDIS_URL
DEBUG
DEBUG_COLORS
DEBUG_FD
DEBUG_MIME
DEBUG_NOPT
EXPRESS_BIND_ADDRESS
EXPRESS_PASSWORD
EXPRESS_PORT
EXPRESS_STATIC
EXPRESS_USER
HEROKU_URL
HOME
HOSTNAME
HTTP_PROXY
HTTPS_PROXY
HUBOT_ADAPTER
HUBOT_ALIAS
HUBOT_ANSWER_TO_THE_ULTIMATE_QUESTION_OF_LIFE_THE_UNIVERSE_AND_EVERYTHING
HUBOT_AUTH_ADMIN
HUBOT_BITLY_API_KEY
HUBOT_BITLY_USERNAME
HUBOT_CAMPFIRE_ACCOUNT
HUBOT_CAMPFIRE_ROOMS
HUBOT_CAMPFIRE_TOKEN
HUBOT_CREATE
HUBOT_DNSIMPLE_API_TOKEN
HUBOT_DNSIMPLE_USERNAME
HUBOT_HTTPD
HUBOT_IRC_CONNECT_COMMAND
HUBOT_IRC_DEBUG
HUBOT_IRC_IGNOREINVITE
HUBOT_IRC_IGNORE_USERS
HUBOT_IRC_NICK
HUBOT_IRC_NICKSERV_PASSWORD
HUBOT_IRC_NICKSERV_USERNAME
HUBOT_IRC_PASSWORD
HUBOT_IRC_PORT
HUBOT_IRC_PRIVATE
HUBOT_IRC_REALNAME
HUBOT_IRC_ROOMS
HUBOT_IRC_SEND_NOTICE_MODE
HUBOT_IRC_SERVER
HUBOT_IRC_SERVER_CERT_EXPIRED
HUBOT_IRC_SERVER_FAKE_SSL
HUBOT_IRC_UNFLOOD
HUBOT_IRC_USERNAME
HUBOT_IRC_USESSL
HUBOT_LOG_LEVEL
HUBOT_NAME
HUBOT_PATH
HUBOT_SCRIPTS
HUBOT_SHELL_HISTSIZE
HUBOT_SHELL_USER_ID
HUBOT_SHELL_USER_NAME
HUBOT_SHIP_EXTRA_SQUIRRELS
HUBOT_TELL_ALIASES
HUBOT_TELL_RELATIVE_TIME
HUBOT_WEB_TITLE_LEN
HUBOT_YOUTUBE_API_KEY
HUBOT_YOUTUBE_DETERMINISTIC_RESULTS
HUBOT_YOUTUBE_HEAR
NAMER_NAME
NAMER_NICK
NODE_DEBUG
NODE_DISABLE_COLORS
NODE_ENV
NODE_NDEBUG
NO_DEPRECATION
NO_PROXY
NOPT_DEBUG
NPM_CONFIG_COVERAGE
NPM_PACKAGE_CONFIG_COVERAGE
PATH
PORT
READABLE_STREAM
REDISCLOUD_URL
REDISTOGO_URL
REDIS_URL
SAUCE_USERNAME
TAP
TAP_COV
TAP_DIAG
TAP_NODIAG
TAP_STDERR
TAP_TIMEOUT
TERM
TRACE_DEPRECATION