feat: Install an unlinked formula via brew install if --overwrite is passed

[boblail]

If the intention is to overwrite any existing links, then brew install should go on to install over an unlinked formula

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same change?
• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your changes? Here's an example.
• Have you successfully run brew style with your changes locally?
• Have you successfully run brew typecheck with your changes locally?
• Have you successfully run brew tests with your changes locally?

---

[boblail]

Hm. I don't think I understand this "Do not report this issue: you are running in an unsupported configuration.\n" error — how it's related to my tests. Does it make sense to one of the maintainers?

[Bo98]

Try temporarily add --debug to see if you get a better error.

[MikeMcQuaid]

Thanks again @boblail, makes sense!

[boblail]

Thanks again, Mike!