Custom board is detected as "Unknown"

[intrigus]

Bug Report

Current behavior

./arduino-cli board list
Port         Type              Board Name FQBN Core
/dev/ttyACM0 Serial Port (USB) Unknown

The connected board is not recognized.

Expected behavior

./arduino-cli board list
Port         Type              Board Name FQBN Core
/dev/ttyACM0 Serial Port (USB) ftduino:avr:ftduino

I'd expect the device to get recognized.
The arduino IDE correctly recognizes it.
The pid and vid are defined in the extension here:
https://github.com/harbaum/ftduino/blob/master/ftduino/boards.txt#L3-L7
Is there something else that needs to be done to recognize a custom board?

Environment

• CLI version (output of arduino-cli version): arduino-cli Version: 0.6.0 Commit: 3a08b07
• OS and platform: Linux.

Additional context

[cmaglie]

It may be that the vid/pid pairs start with the progressive number 1 instead of 0:

ftduino.name=ftDuino
ftduino.vid.1=0x1c40   <--- should be vid.0
ftduino.pid.1=0x0537
ftduino.vid.2=0x1c40
ftduino.pid.2=0x0538

May you try to change the above lines with:

ftduino.name=ftDuino
ftduino.vid.0=0x1c40
ftduino.pid.0=0x0537
ftduino.vid.1=0x1c40
ftduino.pid.1=0x0538

and see if this fixes the problem?