How to install on a Mac?

[boxleytw]

I've ensured modern Ruby is installed in homebrew:

$ which ruby
/usr/local/opt/ruby/bin/ruby
$ ruby --version
ruby 3.0.0p0 (2020-12-25 revision 95aff21468) [x86_64-darwin19]

However when running brew install ronn-ng I get this error:

ERROR:  Error installing /Users/boxley/Library/Caches/Homebrew/downloads/4148d48f83730eefbee6e544b01b21971db08edb1e4133b9fbcf3a166f1f00b1--mustache-1.0.0.gem:
	mustache-1.0.0 requires Ruby version ~> 2.0. The current ruby version is 3.0.0.0.

If reporting this issue please do so at (not Homebrew/brew or Homebrew/core):
  https://github.com/apjanke/homebrew-ronn-ng/issues


Error: A newer Command Line Tools release is available.
Update them from Software Update in System Preferences or run:
  softwareupdate --all --install --force

I've run the system update as suggested (--force was not required), rebooted, same result.

[boxleytw]

And having read the output better ... I'm filing the issue in the wrong place!~