pyenv install 3.9 BUILD FAILED (OS X 12.0.1 using python-build 20180424)

# Install x86 homebrew

arch -x86_64 /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"

alias ibrew="arch -x86_64 /usr/local/bin/brew"

# Install Python 3.9

$ brew install python@3.9

from: https://qiita.com/tsuu/items/50e09d64f5afb5f5b827