Arduino Due Port Issue Revisited

[rmerriam]

I know this issue keeps cropping up. I used my Due's a couple years ago and initially had problems. For some reason it went away. I'm returning to them and the issue is back again. I have two boards both doing the same thing.

Running Ubunutn 16.04.

1. Yes, I'm accessing the correct port. They appear in /dev, lsusb, etc.
2. The Arduino 1.8.5 IDE seems to do the upload properly now but I don't know why. It didn't when I first tried it.
3. I'm using the Eclipse Sloeber plugin because my programs exceed the capacity of the IDE. It doesn't want to upload.

But I've found something interesting. If you omit the port (-p) it works every time from the command line. If you specify the port it fails.

Run this and it uploads:
stty -F /dev/ttyACM0 speed 1200
/home/rmerriam/.arduino15/packages/arduino/tools/bossac/1.6.1-arduino/bossac -d -U false -e -w -b /home/rmerriam/development/Arduino/StrandDev/Due/StrandDev.bin -R
Run this and it doesn't:
stty -F /dev/ttyACM0 speed 1200
/home/rmerriam/.arduino15/packages/arduino/tools/bossac/1.6.1-arduino/bossac -d -U false -e -w -b -p /dev/ttyACM0 /home/rmerriam/development/Arduino/StrandDev/Due/StrandDev.bin -R
No device found on /dev/ttyACM0`

It does the same with bossac installed using the package manager.

[iddq]

No device found on /dev/ttyACM0

I belive that the port changed after board reset from ACM0 to something else like ACM1.