Help required updating the port for TortoiseHG to 6.3.1

[Themanwithoutaplan]

I've started work updating the portfile. Unfortunately, it looks like changes upstream in Python mean a simple update of version and hashes are not sufficient.

When running port -v build against the local repository I get the following error:

Executing:  cd "/opt/local/var/macports/build/_Users_charlieclark_temp_macports-ports_devel_tortoisehg/tortoisehg/work/thg-6.3.1" && /opt/local/Library/Frameworks/Python.framework/Versions/3.10/bin/python3.10 setup.py --no-user-cfg build -j1
/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/setuptools/command/install.py:34: SetuptoolsDeprecationWarning: setup.py install is deprecated. Use build and pip and other standards-based tools.
  warnings.warn()

I'm trying to work out how the build is initiated so that changes can be made but it's not clear to me how the build is initiated by MacPorts. There is a makefile with an "app" target but I can't get that to work either because HGPATH is missing or wrong.

FWIW in the thg repos there is another approach to building the app in contrib/packaging/macos but it looks to me like this is not being called.

Apart from updating the port, I'm hoping improve the build process and docs upstream.