brew doctor errors without giving advice about how to resolve No Cask with this name exists.

[jsoref]

brew config output

HOMEBREW_VERSION: 3.4.3
ORIGIN: https://github.com/Homebrew/brew
HEAD: 600d84e56eda931c3dd3b6a9ee61233d9bf2b054
Last commit: 3 days ago
Core tap ORIGIN: https://github.com/Homebrew/homebrew-core
Core tap HEAD: 938bc3e868b93605f67fb43f836151af4332f6cd
Core tap last commit: 25 hours ago
Core tap branch: master
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_CORE_GIT_REMOTE: https://github.com/Homebrew/homebrew-core
HOMEBREW_MAKE_JOBS: 10
Homebrew Ruby: 2.6.8 => /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/bin/ruby
CPU: 10-core 64-bit arm_firestorm_icestorm
Clang: 13.1.6 build 1316
Git: 2.35.1 => /opt/homebrew/bin/git
Curl: 7.79.1 => /usr/bin/curl
macOS: 12.3-arm64
CLT: 13.3.0.0.1.1645755326
Xcode: N/A
Rosetta 2: false

brew doctor output

Error: Cask 'font-dejavu-sans' is unavailable: No Cask with this name exists.

Verification

• I ran brew update and am still able to reproduce my issue.
• I have resolved all warnings from brew doctor and that did not fix my problem.

What were you trying to do (and why)?

Reproduce Homebrew/homebrew-cask#71221 (comment) to determine that brew doctor's output is indeed very unhelpful.

What happened (include all command output)?

1. Simulate having a font-dejavu-sans cask from before it was removed (?).

mkdir -p /opt/homebrew/Caskroom/font-dejavu-sans

2. run brew doctor

What did you expect to happen?

brew doctor should explain that I have an obsolete cask and what I should do to remove it so that brew doctor can work.

At the very least, it should tell me a full path to things it doesn't like so I at least know where to look (I have two instances of brew installed, the other runs under rosetta).

Step-by-step reproduction instructions (by running brew commands)

mkdir -p /opt/homebrew/Caskroom/font-dejavu-sans
brew doctor

[MikeMcQuaid]

Can I see the output of brew doctor --debug here? Thanks!

[jsoref]

Error: Cask 'font-dejavu-sans' is unavailable: No Cask with this name exists.
/opt/homebrew/Library/Homebrew/cask/cask_loader.rb:196:in `load'
/opt/homebrew/Library/Homebrew/cask/cask_loader.rb:205:in `load'
/opt/homebrew/Library/Homebrew/cask/caskroom.rb:47:in `block in casks'
/opt/homebrew/Library/Homebrew/cask/caskroom.rb:39:in `map'
/opt/homebrew/Library/Homebrew/cask/caskroom.rb:39:in `casks'
/opt/homebrew/Library/Homebrew/cmd/doctor.rb:51:in `doctor'
/opt/homebrew/Library/Homebrew/brew.rb:110:in `<main>'