I'm trying to build 3.6.15 on my M1 using pyenv 2.2.5. I applied the patch listed above by @mikeyh, but I still get errors during the build:   File "/var/folders/41/gktcdg9x6d38d7jhzg09nwsh0000gn/T/tmpgmrcdbol/pip-18.1-py2.py3-none-any.whl/pip/_internal/cli/main_parser.py", line 12, in <module>  File "/var/folders/41/gktcdg9x6d38d7jhzg09nwsh0000gn/T/tmpgmrcdbol/pip-18.1-py2.py3-none-any.whl/pip/_internal/commands/__init__.py", line 6, in <module>  File "/var/folders/41/gktcdg9x6d38d7jhzg09nwsh0000gn/T/tmpgmrcdbol/pip-18.1-py2.py3-none-any.whl/pip/_internal/commands/completion.py", line 6, in <module>  File "/var/folders/41/gktcdg9x6d38d7jhzg09nwsh0000gn/T/tmpgmrcdbol/pip-18.1-py2.py3-none-any.whl/pip/_internal/cli/base_command.py", line 18, in <module>  File "/var/folders/41/gktcdg9x6d38d7jhzg09nwsh0000gn/T/tmpgmrcdbol/pip-18.1-py2.py3-none-any.whl/pip/_internal/download.py", line 38, in <module>  File "/var/folders/41/gktcdg9x6d38d7jhzg09nwsh0000gn/T/tmpgmrcdbol/pip-18.1-py2.py3-none-any.whl/pip/_internal/utils/glibc.py", line 3, in <module>  File "/private/var/folders/41/gktcdg9x6d38d7jhzg09nwsh0000gn/T/python-build.20220509143451.90455/Python-3.6.15/Lib/ctypes/__init__.py", line 7, in <module>   from _ctypes import Union, Structure, Array ModuleNotFoundError: No module named '_ctypes' Any way around that?