I'm currently running OctoPrint 1.3.10 on OctoPi 0.16, Raspberry Pi 3 B+. I have two instances running, connected to two identical Monoprice Mini Delta printers. When I have both printers running at the same time, then one finishes, I will turn that printer off, OctoPrint will note a serial issue and everything is fine.
The problem occurs when I turn the printer back on and the other printer is still printing. There is a likelihood that with the combination of the auto connect function, the "AUTO" serial port and the OctoPrint-PortLister plugin, this idle instance will try to auto connect to the "AUTO" serial port when OctoPrint-PortLister notices the printer return to life. In turn, there's a chance that it will try the serial port the other printer is using, and then kill the running print job with the double connection to the serial port.
I have a udev rules file that identifies my printers by their serial number, so printer 1 will always be /dev/MiniDelta1 and printer 2 will always be /dev/MiniDelta2 regardless of the real /dev/tty* device (which will vary depending on the order the printers were turned on).
I've added the serial port /dev/MiniDelta1 to the first OctoPrint and /dev/MiniDelta2 to the second OctoPrint, but AUTO and /dev/ttyACM* are also there. Is there any way I can can remove the actual /dev/ttyACM* ports from OctoPrint's list, and possibly remove the AUTO port as well? That would leave me with only zero or one serial port options per OctoPrint instance. This way I can keep my dangerous cocktail of auto connect and OctoPrint-PortLister.