I'm having a very similar issue as described in the following post while trying to download GTK:
installing gtk+ on mac osx 10.11.4 El-Capitan
I am following these instructions:
./gtk-osx-build-setup.sh
jhbuild bootstrap
jhbuild build meta-gtk-osx-bootstrap meta-gtk-osx-gtk3
The first two steps complete, however, the last step gets stuck on the follow issue:
"configure: error: Python module libxml2 is needed to run this package"
However, the solution provided at the above Stack Overflow link does not work as the same issue returns when I continue with the build.
If I try to run:
brew install libxml2
I get
Warning: libxml2 is a keg-only and another version is linked to opt.
This seems like it should be easy to fix, but I am not sure what to try next. Please let me know if you have any suggestions!
I never did figure out what was causing that error. In the meantime, I've switched to a different module set and have not encountered it any more. My module set is available here: https://github.com/ptomato/macos-jhbuild
(By the way, you should not mix homebrew packages with JHbuild if you want to build app bundles using your JHbuild installation; you will wind up linking against files that won't go in the bundle.)