heimdall libusb error -1 I am trying to flash TWRP on Samsung Galaxy S6 that I inherited from someone else, there was already some custom software on it, but I am not sure what exactly. File transfer to a computer works fine. The computer I am using has ubuntu 16.04 installed and heimdall from the official repositories v1.4.1) and the following works fine on an S4 mini:

$ heimdall print-pit
Heimdall v1.4.1

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Initialising connection...
Detecting device...
libusb: error [_get_usbfs_fd] libusb couldn't open USB device /dev/bus/usb/001/018: Input/output error
ERROR: Failed to access device. libusb error: -1
The problem must have been on the side of the s6. I was able to run heimdall print-pit successfully, but only for a moment after entering download mode.