gr-osmosdr fail to build with +iio in macOS 10.15.7

[YesNo801]

command to install and build:

$ sudo port install gr-osmosdr +iio

...

Fetching archive for gr-iio
...
--->  Fetching distfiles for gr-osmosdr
--->  Verifying checksums for gr-osmosdr
--->  Extracting gr-osmosdr
--->  Applying patches to gr-osmosdr
--->  Configuring gr-osmosdr

Error: Failed to configure gr-osmosdr: consult Error: Processing of port gr-osmosdr failed

[ryandesign (Ryan Carsten Schmidt)]

The relevant error from the main.log might be:

CMake Error at lib/plutosdr/CMakeLists.txt:30 (target_link_libraries):
  Attempt to add link library "/opt/local/lib/libgnuradio-iio.dylib" to
  target "gnuradio-osmosdr" which is not built in this directory.
  This is allowed only when policy CMP0079 is set to NEW.

Though I also see this which looks a little weird since the port does declare a dependency on gmp (and mpir):

-- Checking for module 'gmp'
--   Found gmp, version 6.2.1
-- Could NOT find GMP (missing: GMPXX_LIBRARY GMP_LIBRARY GMP_INCLUDE_DIR)
-- GMP not found; this is not a problem if MPIR can be found.
-- Checking for module 'mpir >= 3.0'
--   No package 'mpir' found
-- Found MPIR: /opt/local/lib/libmpirxx.dylib 
-- MPIR found
-- Found MPLIB: /opt/local/lib/libmpirxx.dylib