So if I run
brew install python-tk, which should let me build basic GUI apps on Mac with Python, it says:
Error: email@example.com: the bottle needs the Apple Command Line Tools to be installed. You can install them, if desired, with: xcode-select --install
xcode-select --installgives me the following dialogue:
80 hours! To install some command-line tools!
(In fact it soon dropped to a more sensible 8 minutes, via 13, but still.)