SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.
If opening the adapter fails, report the libusb error message in the GUI
instead of “No Adapter Detected”.
The error condition is removed when the adapter is unplugged.