Cannot unplug and re-plug USB Serial device on OSX

[nilbus]

Reported by @everetteallen in #57:

If I unplug and replug "hot" I get:

sudo foreman start
19:42:29 web.1  | started with pid 844
19:42:30 web.1  | Warning: You're using Rubygems 2.0.14 with Spring. Upgrade to at least Rubygems 2.1.0 and run `gem pristine --all` for better startup performance.
19:42:32 web.1  | I, [2015-02-10T19:42:32.521912 #844]  INFO -- : Sensor watch started w/ device search path: "/dev/tty.usbserial"
19:44:15 web.1  | E, [2015-02-10T19:44:15.629024 #844] ERROR -- : Actor crashed!
19:44:15 web.1  | Errno::ENXIO: Device not configured
19:44:15 web.1  |   /Library/Ruby/Gems/2.0.0/gems/celluloid-io-0.15.0/lib/celluloid/io/stream.rb:44:in `block in sysread'
19:44:15 web.1  |   /Library/Ruby/Gems/2.0.0/gems/celluloid-io-0.15.0/lib/celluloid/io/stream.rb:390:in `synchronize'
19:44:15 web.1  |   /Library/Ruby/Gems/2.0.0/gems/celluloid-io-0.15.0/lib/celluloid/io/stream.rb:42:in `sysread'
19:44:15 web.1  |   /Library/Ruby/Gems/2.0.0/gems/celluloid-io-0.15.0/lib/celluloid/io/stream.rb:322:in `fill_rbuff'
19:44:15 web.1  |   /Library/Ruby/Gems/2.0.0/gems/celluloid-io-0.15.0/lib/celluloid/io/stream.rb:159:in `gets'
19:44:15 web.1  |   /Library/Ruby/Gems/2.0.0/gems/celluloid-io-0.15.0/lib/celluloid/io/stream.rb:181:in `each'
19:44:15 web.1  |   /Users/ega/pinewood-derby-master/lib/serial_device.rb:33:in `monitor_input'
19:44:15 web.1  |   /Library/Ruby/Gems/2.0.0/gems/celluloid-0.16.0/lib/celluloid/calls.rb:26:in `public_send'
19:44:15 web.1  |   /Library/Ruby/Gems/2.0.0/gems/celluloid-0.16.0/lib/celluloid/calls.rb:26:in `dispatch'
19:44:15 web.1  |   /Library/Ruby/Gems/2.0.0/gems/celluloid-0.16.0/lib/celluloid/calls.rb:122:in `dispatch'
19:44:15 web.1  |   /Library/Ruby/Gems/2.0.0/gems/celluloid-0.16.0/lib/celluloid/cell.rb:60:in `block in invoke'
19:44:15 web.1  |   /Library/Ruby/Gems/2.0.0/gems/celluloid-0.16.0/lib/celluloid/cell.rb:71:in `block in task'
19:44:15 web.1  |   /Library/Ruby/Gems/2.0.0/gems/celluloid-0.16.0/lib/celluloid/actor.rb:357:in `block in task'
19:44:15 web.1  |   /Library/Ruby/Gems/2.0.0/gems/celluloid-0.16.0/lib/celluloid/tasks.rb:57:in `block in initialize'
19:44:15 web.1  |   /Library/Ruby/Gems/2.0.0/gems/celluloid-0.16.0/lib/celluloid/tasks/task_fiber.rb:15:in `block in create'

My derby_config.yml is:

admin_password: <%= ENV['DERBY_ADMIN_KEY'] %>
# device_glob: "/dev/tty{USB,.usbserial}*"
device_glob: "/dev/tty.usbserial"
lane_count: 3
sensor_class_name: MicroWizardFastTrack

[nilbus]

@everetteallen Unfortunately right now I don't have a USB serial adapter to test with, and my free time is limited. For now, you may have to restart the rails app server if the USB device gets unplugged. Restarting the server will not cause any data loss, as everything is persisted in the database.

[nilbus]

@everetteallen Can you confirm that you can receive data from the track sensor up until you unplug the USB adapter? It seems like it, since the log shows nearly 2 minutes between the app startup and the actor crash.