You have been subscribed to a public bug: We're running into a weird bug on Ubuntu : WebUSB works on Chrome but doesn't on Chromium!
Here's our udev rule: https://workshop.numworks.com/files/drivers/linux/50-numworks- calculator.rules It uses the uaccess tag which adds an ACL to the created file in /dev/ so that the current logged-in user has RW access to the corresponding /dev/bus/usb/** device. Apparently that's the way to go, since relying on groups is fragile (not all distros use the "plugdev" group for example). That udev rules works just fine. When using a command-line utility such as "dfu-tool", the USB device is seen and can be read from and written to. It also works just fine on Chrome. But Chromium gives us an "access denied" error. It lists the device, we do get the pop-up, but we cannot communicate. On Chromium, chrome://device-log says : Failed to open /dev/bus/usb/001/011: Operation not permitted (1) Here are the infos on said file: user@virtualbox:~$ ls -l /dev/bus/usb/001/011 crw-rw-r--+ 1 root root 189, 10 Jul 3 11:35 /dev/bus/usb/001/011 As you can see, the file is owned root/root, but has an ACL (as shown by the "+" symbol) user@virtualbox:~$ getfacl /dev/bus/usb/001/011 getfacl: Removing leading '/' from absolute path names # file: dev/bus/usb/001/011 # owner: root # group: root user::rw- user:user:rw- group::rw- mask::rw- other::r-- Here the ACL supposedely gives RW access to "user" who is indeed the current logged-in user, and the user running Chromium and Chrome. For reference : - Latest stable Ubuntu (18.04) - Using the Chromium that ships with Ubuntu (from the Ubuntu Software app. attached chrome://version page) - And using latest stable Chrome from google.com (attached chrome://version page) ** Affects: chromium-browser (Ubuntu) Importance: Undecided Status: New -- Chromium cannot use WebUSB https://bugs.launchpad.net/bugs/1780678 You received this bug notification because you are a member of Desktop Packages, which is subscribed to chromium-browser in Ubuntu. -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp