[GNU Radio 3.8] Error loading modules on E310

Dear all,

finally I cross-compiled my OOT module for running on USRP E310.

Based on the instructions at "https://kb.ettus.com/Software_Development_on_the_E3xx_USRP_-_Building_RFNoC_UHD_/_GNU_Radio_/_gr-ettus_from_Source", I set the environment variable PYTHONPATH a little bit different, to point the path of the installed OOT module:

export PYTHONPATH=$LOCALPREFIX/lib/python3.5/dist-packages:$PYTHONPATH

Such a way, on the target I can load my custom module in python.

root@ni-e31x-316AFEA:~# python3 -c "import custom_mod"

I created a flowgraph that use my OOT module, and I discovered in the newer file system for E310 python3 has not all of the needed libraries.

root@ni-e31x-316AFEA:~# ./top_block.py
Traceback (most recent call last):
  File "./top_block.py", line 12, in <module>
    from gnuradio import blocks
  File "/home/root/localinstall/usr/lib/python3.5/dist-packages/gnuradio/blocks/__init__.py", line 38, in <module>
    from .stream_to_vector_decimator import *
  File "/home/root/localinstall/usr/lib/python3.5/dist-packages/gnuradio/blocks/stream_to_vector_decimator.py", line 23, in <module>
    from gnuradio import gr
  File "/home/root/localinstall/usr/lib/python3.5/dist-packages/gnuradio/gr/__init__.py", line 46, in <module>
    from .top_block import *
  File "/home/root/localinstall/usr/lib/python3.5/dist-packages/gnuradio/gr/top_block.py", line 32, in <module>
    from .hier_block2 import hier_block2
  File "/home/root/localinstall/usr/lib/python3.5/dist-packages/gnuradio/gr/hier_block2.py", line 26, in <module>
    import pmt
  File "/home/root/localinstall/usr/lib/python3.5/dist-packages/pmt/__init__.py", line 61, in <module>
    from .pmt_to_python import pmt_to_python as to_python
  File "/home/root/localinstall/usr/lib/python3.5/dist-packages/pmt/pmt_to_python.py", line 23, in <module>
    import numpy
ImportError: No module named 'numpy'

How could I solve the problem?

I'm so close to run my OOT modules on the target...

Thanks so much.

Ivan