It does not work with python3.8 either.

$ make -s regen-all PYTHON_FOR_REGEN=python3.8
./Include/opcode.h.new regenerated from ./Lib/opcode.py
Jump table written into ./Python/opcode_targets.h.new
Traceback (most recent call last):
  File "/usr/lib/python3.8/runpy.py", line 192, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/usr/lib/python3.8/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/home/serhiy/py/cpython/Tools/peg_generator/pegen/__main__.py", line 16, in <module>
    from pegen.build import build_parser_and_generator
  File "/home/serhiy/py/cpython/Tools/peg_generator/pegen/build.py", line 13, in <module>
    from distutils.tests.support import fixup_build_ext
ModuleNotFoundError: No module named 'distutils.tests'
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 63, in apport_excepthook
    from apport.fileutils import likely_packaged, get_recent_crashes
  File "/usr/lib/python3/dist-packages/apport/__init__.py", line 5, in <module>
    from apport.report import Report
  File "/usr/lib/python3/dist-packages/apport/report.py", line 30, in <module>
    import apport.fileutils
  File "/usr/lib/python3/dist-packages/apport/fileutils.py", line 23, in <module>
    from apport.packaging_impl import impl as packaging
  File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 24, in <module>
    import apt
  File "/usr/lib/python3/dist-packages/apt/__init__.py", line 23, in <module>
    import apt_pkg
ModuleNotFoundError: No module named 'apt_pkg'

Original exception was:
Traceback (most recent call last):
  File "/usr/lib/python3.8/runpy.py", line 192, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/usr/lib/python3.8/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/home/serhiy/py/cpython/Tools/peg_generator/pegen/__main__.py", line 16, in <module>
    from pegen.build import build_parser_and_generator
  File "/home/serhiy/py/cpython/Tools/peg_generator/pegen/build.py", line 13, in <module>
    from distutils.tests.support import fixup_build_ext
ModuleNotFoundError: No module named 'distutils.tests'
Makefile:837: recipe for target 'regen-pegen' failed
make: *** [regen-pegen] Error 1