Hi all, just FYI I will likely be moving the Homebrew IMP package to Python 3.8 in the near future.
The Homebrew folks seem to be having a lot of trouble switching from Python 3.7 to 3.8; see https://github.com/Homebrew/homebrew-core/issues/47274 which they have been working on since November. They gave up on a simple switch and now they are migrating formulae individually. Most formulae now use Python 3.8 but the default (/usr/local/bin/python3) is still 3.7. Since IMP uses the default it is increasingly broken since common dependencies (numpy, scipy) now only work with 3.8.
If you want to build IMP on a Homebrew Mac against Python 3.8, this is pretty easy - just set in bashrc/zshrc export PATH="/usr/local/opt/python@3.8/bin:$PATH" as recommended by "brew info python@3.8" to make "python3" be 3.8 and export CMAKE_FRAMEWORK_PATH="/usr/local/Cellar/python@3.8/3.8.2/Frameworks" for CMake to pick up 3.8 when you build IMP.
I will likely also adjust the Homebrew IMP package to use Python 3.8 at some point in the next few weeks.
Ben