What does this error mean - Raspberry PI 4

[brianreinhold]

I get this error when I call the method SerialPort.getSerialPorts()

ERROR: This is a very bad thing that should never happen /home/runner/work/JavaSerial/JavaSerial/main/NativeCode/SerialPortImpl.c:1952 errno:6

Its just a 'No such device or address' BUT it causes the system to crash and reboot - sometimes immediately and sometimes not until after about a 10-20 seconds. Looking at the C code where this error occurs it is not clear to me why this should cause a crash unless the errors are not handled at all.

Never see this error on Windows 10

I see it on Raspberry PI 3 versions too.

[rm5248]

Errno 6 is apparently 'no such device or address.' I would be surprised if this caused the system to reboot, since all it is doing is attempting to open the device to see if it is a tty. Simply attempting to open a device should not cause the system to reboot.

[brianreinhold]

Yea, I don't get it. I have noted when I run the app as root the error is much more likely to cause a reboot. The weird thing is that I get the error EVEN when the SerialPort.getSerialPorts() returns a non-empty list (for example I have a cable connected. As root, the reboot still occurs. I don't know how to debug it.

[rm5248]

You could try using cat to read something from every file, see if that causes a reboot.