> However as I wrote before[1] it is need to specify SWIG_PY_OPTS > shell/environment variable to generate SWIG Python bindings C source > and support codes. The value of SWIG_PY_OPTS depends on which is its > target py2 or py3, on which SWIG version is prior 4.0 or not.
This was the key thing lacking! When I added the SWIG_PY_OPTS stuff you recommended to the release.py command-line, those files generated as expected. (And I wound up with what appears to be working build, including Python3 bindings.)
