Responsible for resolving any issues

[agjftucker]

It doesn't seem very fair to put this on me. I did not press RETURN when I got this warning. I pressed ESC, pretty much the opposite of RETURN. Yet the bloody thing proceeded regardless.

You are using macOS 10.13.
==> We (and Apple) do not provide support for this old version.
This installation may not succeed.
After installation, you will encounter build failures with some formulae.
Please create pull requests instead of asking for help on Homebrew's GitHub,
Twitter or IRC. You are responsible for resolving any issues you experience
while you are running this old version.

Press RETURN to continue or any other key to abort

[SMillerDev]

You can just uninstall homebrew again https://docs.brew.sh/FAQ#how-do-i-uninstall-homebrew

If it didn't cancel as expected you can create an issue for that at https://github.com/Homebrew/install/issues

[tlk]

Their script should be testing whether brew is installed

Just out of curiosity, is it documented anywhere that the Homebrew installer script will wipe out an existing Homebrew installation?

[carlocab]

Does it wipe out an existing Homebrew installation?

[tlk]

I don't know - but it did something that the OP thought was undesirable. Is this documented somewhere?

[carlocab]

Sorry, but I still don't know what you're looking to be documented here. Running the install script when you have an existing Homebrew install might make you feel bad.?

[agjftucker]

Does it wipe out an existing Homebrew installation?

Certainly it listed many hundreds of "Deleted Formulae" and "Deleted Casks" before I stopped it. I gave up on today after that so it remains to be seen what is the final impact on my working environment. Naturally I remain concerned given the warning "You will encounter build failures ... You are responsible for resolving any issues".

To be clear I think the warning would have been a perfectly adequate guard ... if it had responded to keyboard input as it promised. I'm still not clear why other programs called by this script were able to respond to keyboard input correctly, but for this one not doing so is "expected behaviour".