Also don't use Homebrew on MacOS because it screws around in /usr/local and still hasn't worked out how root is supposed to work.

Use Macports, it's tidy, installs into /opt/macports, works with Apple's frameworks and language configuration (for python, java etc), builds from upstream sources + patches, has variants to add/remove features, supports "port select" to have multiple versions installed in parallel.

Just a better solution all around.