"Could not initialize libusb. Check that your system has a usb controller." on Travis CI

For some reason I get that error only when running inside a Travis CI job.

I tracked down the error to libusb_init (http://libusb.sourceforge.net/api-1.0/group__lib.html#ga9517c37281bba0b51cc62eba728be48b). Do you have any clues about why that’s failing, and how we can at least workaround it?

[kevinmehall]

@agirorn If you want to make a PR removing this throw, I think the better API would be to check whether initialization failed in getDeviceList and anything else that can be called without a device, and make those functions throw an exception.

[agirorn]

Why does this module throw this error here usb.js#L11 this means that every code that requires this module needs to guard it is self against this (bug I think) even if it is not going to use the USB, and just wants go require it in the top of the js file and then later on do some feature detection.

Since the property INIT_ERROR is already on the module it should be enough to silently ignore this and allow the user of the module to decide how he want’s to handle this scenario.

Would you accept a pull request that removes this check and adds the available function a simple and clean API to check if USB has been detected?

usb.available = () => !usb.INIT_ERROR;