try python-config --ldflags --embed first

try python-config --ldflags --embed first

As of python 3.8, output of "python-config --ldflags" no longer includes
the "-lpython" flag without which the python module fails to link due to
undefined symbols. Use "python-config --ldflags --embed" to get it back
and fall back to "python-config --ldflags" for python 3.7 and older.

https://docs.python.org/3.8/whatsnew/3.8.html#debug-build-uses-the-same-abi-as-release-build