Cannot Connect Using WebUSB (Chromium + Arch Linux)

[Jazztache]

Hello!

I am on Arch Linux 6.17.4-arch2-1
I am having a lot of trouble getting the Ctrl application to detect the Inputlabs Alpakka.

I can add the device via the interface in Chromium, and Ctrl does detect it as an Alpakka. However, I get the following error on the native pacman-installed version of Chromium:

SecurityError: Failed to execute 'open' on 'USBDevice': Access denied.

This happens under both Hyprland and KDE Plasma desktops.

I have the following udev rules installed at:
/etc/udev/rules.d/99-alpakka.rules

SUBSYSTEMS=="usb", ATTRS{idVendor}=="045e", MODE="0660", GROUP="plugdev", SYMLINK+="webusb"
SUBSYSTEMS=="usb", ATTRS{idVendor}=="0170", MODE="0660", GROUP="plugdev", SYMLINK+="webusb" 

Here is what I have tried:

• Following the troubleshooting steps on the setup page for Arch Linux
• Brave and Chromium
• Putting the controller into XInput Linux mode using Ctrl on Windows
  • I also cannot access the Ctrl app on Windows now... I'm using someone else's Win 11 device.
  • The Ctrl app doesn't detect XInput Linux from what I can tell
  • This makes it appear as 'Microsoft Corp. Xbox360 Controller' instead of 'InputLabs Alpakka', which I think is expected behaviour.
• Unplugging the controller, restarting chromium and plugging it back in again.

No matter what I do, I cannot get /dev/webusb to exist:
/dev/webusb: cannot open /dev/webusb' (No such file or directory)`

Note: I haven't gotten the thumbstick or scrollwheel in yet, so no tune access right now. Using the controller unsealed for a little bit to test the firmware. I can access profiles, the LEDs work, and I have recently reflashed the firmware correctly as per the instructions on the website. I also recalibrated the controller.

What should I do to fix this?
Should I try the flatpak build of Chromium?

I am out of options and I am not sure what to do. Any help would be appreciated. I also need to fix this in order to better debug an issue with the gyro not initialising.

Thankyou!

[Jazztache]

Solved this! However, it's a per-user fix. In this thread: https://bbs.archlinux.org/viewtopic.php?pid=2276566#p2276566, I figure out the udev rules for base Arch Linux. Please update the instructions to use these rules, but altered to leave out the /tmp/ files. The final udev rules I ended up with are in the last post I made in the thread.