Cannot specify link libraries for target "Python::NumPy"

All:

I'm building gnuradio from source on an Ubuntu 18.04.6 system.

I'm using the instructions from: https://wiki.gnuradio.org/index.php/InstallingGR#From_Source

When I get to the step:

# Note: In the following command, you can add -DCMAKE_INSTALL_PREFIX=XXX to install GNU Radio into the PREFIX XXX; if not specified, then the PREFIX is /usr/local. See other CMake options in Common cmake flags.

cmake -DCMAKE_BUILD_TYPE=Release -DPYTHON_EXECUTABLE=/usr/bin/python3 ../

I get an error relating to numpy:

-- User set python executable /usr/bin/python3
CMake Error at cmake/Modules/GrPython.cmake:101 (target_link_libraries):
  Cannot specify link libraries for target "Python::NumPy" which is not built
  by this project.
Call Stack (most recent call first):
  CMakeLists.txt:318 (include)

-- Configuring incomplete, errors occurred!

numpy is installed and I can 'import numpy' successfully in python3. (In fact I had issued "apt-get install *numpy*" previously and it was successful.)

I tried finding this error in my archive of gnuradio discussion-list emails, but came up empty, as did my google search.

Any advice?

Thanks,

C

--   Chad M. Spooner, PhD  NorthWest Research Associates  301 Webster Street  Monterey, CA 93940  cmspooner@nwra.com  831 582 4904  cyclostationary.blog