USB CDC ACM device 303a:1001 binds to cdc_acm and creates /sys/class/tty/ttyACM0, but no /dev/ttyACM0 is created, and manually mknod’d 166:0 returns EPERM even as root. When I attach the device through the UI and run

dmesg

, I see this output:

[271430.202155] usb 1-1: Product: USB JTAG/serial debug unit
[271430.202157] usb 1-1: Manufacturer: Espressif
[271430.202165] usb 1-1: SerialNumber: 98:A3:16:8F:84:F8
[271430.205751] cdc_acm 1-1:1.0: ttyACM0: USB ACM device

So the device is successfully being identified by the kernel but I'm unable to access it.

fixed for the next version