`brew tests` should pass with `homebrew/core` untapped about brew

[MikeMcQuaid]

print a warning that failures are expected (w/ instructions to run brew tap --force homebrew/core).

Do you have an example of some failures that occur?

What alternatives to the feature have been considered?

Another option could be fixing up tests so homebrew/core isn't required to be tapped.

[rrotter]

Good point. There are 64 failures, every one of them is in rubocops/uses_from_macos or rubocops/provided_by_macos.

[Bo98]

That's useful info - thanks!

This will be because https://github.com/Homebrew/brew/blob/master/Library/Homebrew/test/support/helper/spec/shared_examples/formulae_exist.rb doesn't support API-only installs yet (but should).

If it turns out tricky to fix then skipping the test under such environments could be a compromise.

[MikeMcQuaid]

This will be because master/Library/Homebrew/test/support/helper/spec/shared_examples/formulae_exist.rb doesn't support API-only installs yet (but should).

Yeh, this feels like the best scope for this issue 👍🏻