Start error TypeError: Cannot read property 'toLowerCase' of undefined

[hbrks]

lwmqn-demo/node_modules/mqtt-node/lib/init.js:189
qn.mac = info.mac_address.toLowerCase();
^

TypeError: Cannot read property 'toLowerCase' of undefined
at /home/hbrks/DEV/lwmqn-demo/node_modules/mqtt-node/lib/init.js:189:43
at /home/hbrks/DEV/lwmqn-demo/node_modules/network/lib/index.js:113:11
at ChildProcess.exithandler (child_process.js:265:7)
at ChildProcess.emit (events.js:180:13)
at maybeClose (internal/child_process.js:936:16)
at Socket.stream.socket.on (internal/child_process.js:353:11)
at Socket.emit (events.js:180:13)
at Pipe._handle.close [as _onclose] (net.js:541:12)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! lwmqn-demo@0.4.0 start: cross-env NODE_ENV=production node main
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the lwmqn-demo@0.4.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR! /home/hbrks/.npm/_logs/2019-01-28T11_57_13_055Z-debug.log

2019-01-28T11_57_13_055Z-debug.log

[amer8]

@hbrks thanks for the error report. we have to update the dependency mqtt-shepherd first, as its build is broken on 9.x and later..
Until then you can run lwmqn-demo on 8.x without problems.