Verification

• This issue's title and/or description do not reference a single formula e.g. brew install wget. If they do, open an issue at https://github.com/Homebrew/homebrew-core/issues/new/choose instead.

Provide a detailed description of the proposed feature

If HOMEBREW_BOTTLE_DOMAIN is set, brew install tries to download portable-ruby from HOMEBREW_BOTTLE_DOMAIN. The location support only unauthenticated requests. However

What is the motivation for the feature?

I'm currently evaluate homebrew on a private environment with restricted internet access. And would like to download the portable-ruby from a private artifact store.

How will the feature be relevant to at least 90% of Homebrew users?

No :/

What alternatives to the feature have been considered?

Using a real authenticated user may work, but we would like to not distribute credentials, since the store this public anyways.

It would be great, if the hardcoded Authentication Header could be omit.