Sometimes even Brew Doctor doesn't fix things or really explain what's going on

Homebrew is usually pretty good at explaining what's going on. However, sometimes the error messages are a bit confusing.

fatal: could not read Username for '': terminal prompts disabled`
Error: Fetching /usr/local/Homebrew/Library/Taps/qameta/homebrew-allure failed!

This error message implies that you have a github setting wrong somewhere. Like maybe you cleared your username? However, I never setup any sort of Github authentication for Brew. Also, its extremely unlikely I'd set one up without ssh keys. So what's going on here?

After some reseraching, I finally found that homebrew-allure package. It lead to a repository on Gitub that doesn't exist anymore. Looks like the owner took it down. Ok. not cool, but his/her perogative. Guess we have to remove from our list of taps. Now that we know what the issue is, fixing it is easy.

brew tap (list all taps)

brew untapcaskroom/cask

Let's get rid of the offending tap.
brew untap qameta/allure

Now we can fix everything and upgrade again

brew doctor
brew update
brew upgrade