Device tracker with "nmap" seems to be broken

I have exactly four days of experience with Home Assistant, so if I’m missing something obvious, please pardon in advance.

**Edit:**  While the issue below is still true, further testing has shown that this is only a problem when running as a service on OSX, ie. when using the ` --install-osx` option.  Running `hass` in a normal shell works fine.  This led me to consider a likely problem with the PATH specified in the **plist** file, which after a fair amount of testing turned out to be true.  So, instead of a problem with the `device_tracker` or `nmap` implementation, this appears to be an issue with the **plist** file generated by the ` --install-osx` option.  The problem here is that anytime you use `--install-osx`, the **plist** file is rebuilt, meaning that you have to manually modify it again with the correct PATH value.  Here is the fix for the **plist** file on my system:

    <key>EnvironmentVariables</key>
    <dict>
       <key>PATH</key> <string>/Library/Frameworks/Python.framework/Versions/3.5/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin</string>
    </dict>

Once the plist file has been manually modified, you can use `launchctl load` and `unload` as required to stop and start the service on OSX.

Running on OSX, I had a device tracker based on “nmap” to scan for a single IP address working fine for a simple automation. Then, just a few minutes ago I updated, and it no longer works. I see the following in the log. Also note that the “pip3” update claims to have updated to modules: Successfully installed requests-2.10.0 setuptools-20.10.1

INFO:homeassistant.components.device_tracker.nmap_tracker:Scanning
INFO:homeassistant.components.http:"GET /states HTTP/1.1" 200 -
INFO:homeassistant.components.http:"GET /static/webcomponents-lite.min.js HTTP/1.1" 200 -
INFO:homeassistant.components.http:"GET /static/favicon-192x192.png HTTP/1.1" 200 -
INFO:homeassistant.components.http:"GET /static/frontend-ffd8a1bde5ba13f300c3d6ad32036526.html HTTP/1.1" 200 -
ERROR:homeassistant.core:BusHandler:Exception doing job
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/homeassistant/core.py", line 801, in job_handler
    func(arg)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/homeassistant/helpers/event.py", line 176, in pattern_time_change_listener
    action(now)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/homeassistant/components/device_tracker/__init__.py", line 393, in device_tracker_scan
    for mac in scanner.scan_devices():
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/homeassistant/components/device_tracker/nmap_tracker.py", line 71, in scan_devices
    self._update_info()
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/homeassistant/util/__init__.py", line 289, in wrapper
    result = method(*args, **kwargs)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/homeassistant/components/device_tracker/nmap_tracker.py", line 121, in _update_info
    mac = info['addresses'].get('mac') or _arp(ipv4)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/homeassistant/components/device_tracker/nmap_tracker.py", line 46, in _arp
    arp = subprocess.Popen(cmd, stdout=subprocess.PIPE)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/subprocess.py", line 950, in __init__
    restore_signals, start_new_session)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/subprocess.py", line 1544, in _execute_child
    raise child_exception_type(errno_num, err_msg)
FileNotFoundError: [Errno 2] No such file or directory: 'arp'

Here’s the “device_tracker” definition. And since I’m on the topic, what is the syntax for giving a name to a specific entry? I found several references to such a thing in the documentation (“paulus”) but nothing that actually shows how to define them.

device_tracker:
  platform: nmap_tracker
  home_interval: 10
  hosts: 10.0.0.180

Possible duplicate:

https://github.com/home-assistant/home-assistant/issues/1632