[esp32s3] espflash flash -M /dev/ttyUSB0 return Error: × Device or resource busy (os error 16)

[Gloopweaqq]

I am using WSL 2.5.10.0 and forwarding the port to WSL from Windows using usbipd.

usbipd: info: Using WSL distribution 'Ubuntu' to attach; the device will be available in all WSL 2 distributions.
usbipd: info: Detected networking mode 'nat'.
usbipd: info: Using IP address 172.21.208.1 to reach the host.

Then I find my port using lsusb. I can see him. Next, using ls -l /dev/serial/by-id/, I find a stable path to the port.
Next, espflash flash -M /dev/serial/by-id/usb-1a86_USB_Serial-if00-port0 and I get the following error:

[2025-08-19T13:35:55Z INFO ] Serial port: '/dev/ttyUSB0'
[2025-08-19T13:35:55Z INFO ] Connecting...
[2025-08-19T13:35:55Z INFO ] Using flash stub
Error:   × Device or resource busy (os error 16)

I tried to clean up all the processes that could somehow interfere:

sudo systemctl stop ModemManager 2>/dev/null || true; sudo systemctl stop brltty 2>/dev/null || true; sudo apt -y purge brltty modemmanager 2>/dev/null || true; sudo fuser -k /dev/ttyACM0 /dev/ttyUSB0 2>/dev/null || true; sudo rm -f /var/lock/LCK..ttyACM0 /var/lock/LCK..ttyUSB0 2>/dev/null || true

Tried espflash flash -M --no-stub
I reset the board, reconnected the wires, tried to use different boards, but nothing helped.
I checked with handle that no one owned the port.
used picocom, which worked.
I would be very grateful if someone could help.

[SergioGasquez]

Hi! I dont have windows nor WSL, so I cant really help you. Have you followed the instructions in https://github.com/esp-rs/espflash/tree/main/espflash#windows-subsystem-for-linux? I would suggest asking in the matrix channel if the previous link didnt help