[gtk-osx-users] Python3 and jhbuild

[John Ralls <jralls ceridwen us>]

I learned a couple of weeks ago that sometime in the last 9 months or so jhbuild had grown the ability to use 
python3 and that as of a month ago it's required on master. As a temporary workaround I froze checkouts to 
the last release (mid-March).

Temporary time is over and I'm about to push changes to jhbuildrc-gtk-osx and gtk-osx-setup.sh that will run 
jhbuild with the venv's python3 instead of /usr/bin/python and I"ll remove the freeze on the jhbuild version. 
That won't affect existing installations unless you run gtk-osx-setup.sh to replace ~/.config/jhbuildrc. If 
you do be sure to also remove $DEVPREFIX/libexec/jhbuild.py so that it gets restored with the python3 
changes. This has the salutary side effect of fixing the broken distutils build module.

The basic example jhbuildrc-custom doesn't need any changes, but if you have a more sophisticated one you 
might want to run 2to3 on it. The 2to3 shipped with Catalina is from 2.7 (and named /usr/bin/2to3-) so you 
might prefer to use the one in the venv:
   PYENV_ROOT=$HOME/.local/share/pyenv pipenv run 2to3 ~/.config/jhbuildrc-

Some other changes coming shortly: It's time to bump the minimum macOS version again, to 10.11 El Capitan. 
The only place this is enforced is jhbuildrc-gtk-osx, so it's easy enough to change if you want to keep 
working on an older version.

I've got an Apple Hardware Developer Transition Kit and have been testing. I'm happy to report that 
everything works so far and that I've already pushed some changes to jhbuildrc-gtk-osx that support the new 
architecture. For those of you who've been around long enough to remember ppc and universal builds, they're 
back. I've no idea if gtk-osx can build one.

Regards,
John Ralls