title: openocd **Error: libusb_open() failed with LIBUSB_ERROR_NOT_SUPPORTED**
body: <p>I am trying to setup a eclipse development environment to work with stm32f303 nucleo 32 board.
  <a href="http://www.st.com/en/evaluation-tools/nucleo-f303k8.html" rel="noreferrer">http://www.st.com/en/evaluation-tools/nucleo-f303k8.html</a></p>
  
  <p>So far, the all the tools seems to be correctly installed and working: I have succefully compiled and started openocd debugger for stm32f4 discovery and when I connect stm32f303 nucleo 32 board and start openocd, the led on the board indicates that it is connected. (I have flashed the board.)</p>
  
  <p>The thing is openocd get lost when I do step by step debugging and this seems related to the message openocd gives me when started (look for bold line):</p>
  
  <pre><code>Open On-Chip Debugger 0.9.0 (2015-05-19-12:09)
  Licensed under GNU GPL v2
  For bug reports, read
      http://openocd.org/doc/doxygen/bugs.html
  adapter speed: 1000 kHz
  adapter_nsrst_delay: 100
  Info : The selected transport took over low-level target control. The results might differ compared to plain JTAG/SWD
  none separate
  srst_only separate srst_nogate srst_open_drain connect_deassert_srst
  Info : Unable to match requested speed 1000 kHz, using 950 kHz
  Info : Unable to match requested speed 1000 kHz, using 950 kHz
  Info : clock speed 950 kHz
  **Error: libusb_open() failed with LIBUSB_ERROR_NOT_SUPPORTED**
  Info : STLINK v2 JTAG v27 API v2 SWIM v15 VID 0x0483 PID 0x374B
  Info : using stlink api v2
  Info : Target voltage: 3.239293
  Info : stm32f3x.cpu: hardware has 6 breakpoints, 4 watchpoints
  </code></pre>
  
  <p>Does someone know how to fix usb driver in that case, or it is possible that something else cause the problem?</p>