(While starting gnuradio-companion-3.7.5, we've got
|  /usr/pkg/lib/python2.7/site-packages/wx-2.8-gtk2-unicode/wx/_core.py:14486:
 UserWarning: wxPython/wxWidgets release number mismatch
|    warnings.warn("wxPython/wxWidgets release number mismatch")
with the combination of
      wxGTK28-2.8.12nb7   GTK-based implementation of the wxWidgets GUI library
      wxGTK28-contrib-2.8.12nb3 Contrib libraries for wxWidgets GTK
      py27-wxWidgets-2.8.10.1nb27 Python bindings for wxWidgets
      gnuradio-wxgui-3.7.5 WxGTK Toolkit module of GNU Radio
That's why:
Import py27-wxWidgets-2.8.12.0 as wip/py-wxWidgets.

wxPython is a set of Python bindings for the powerful wxWidgets
cross-platform GUI library.
Add three lines:
+
+## CMake Error at CMakeLists.txt:69 (message):
+##   LibUSB 1.0 required to compile rtl-sdr
+CMAKE_ARGS+=   -DLIBUSB_INCLUDE_DIR=${PREFIX}/include/libusb-1.0