brew install not respecting tap when formula name collides with core

[amancevice]

brew doctor output

Your system is ready to brew.

Verification

• My "brew doctor output" above says Your system is ready to brew. and am still able to reproduce my issue.
• I ran brew update twice and am still able to reproduce my issue.
• 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.

brew config output

HOMEBREW_VERSION: 4.1.20-2-gd72ee37
ORIGIN: https://github.com/Homebrew/brew
HEAD: d72ee37f60e287e833ef9b1882bc6ca8ded01aea
Last commit: 2 hours ago
Core tap JSON: 13 Nov 15:42 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_BROWSER: open
HOMEBREW_CASK_OPTS: []
HOMEBREW_EDITOR: vi
HOMEBREW_MAKE_JOBS: 8
HOMEBREW_SORBET_RUNTIME: set
Homebrew Ruby: 2.6.10 => /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/bin/ruby
CPU: octa-core 64-bit arm_firestorm_icestorm
Clang: 15.0.0 build 1500
Git: 2.42.1 => /opt/homebrew/bin/git
Curl: 8.4.0 => /usr/bin/curl
macOS: 14.2-arm64
CLT: 15.0.0.0.1.1694021235
Xcode: 15.0
Rosetta 2: false

What were you trying to do (and why)?

I want to install terraform from hashicorp/tap:

brew install hashicorp/tap/terraform

What happened (include all command output)?

brew is preferring the formula in homebrew/core

What did you expect to happen?

I expect brew to respect the tap prefix in my command and install from there.

Note this definitely seems related to 97b4119 as when I checkout 4.1.20 (the previous commit) the issue goes away.

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

brew install hashicorp/tap/terraform                                                                                                   ⌘ /opt/homebrew/Library
==> Downloading https://ghcr.io/v2/homebrew/core/terraform/manifests/1.5.7
Already downloaded: /Users/spice/Library/Caches/Homebrew/downloads/2765dc205c0f89c57475889f81e01a98697bdbcbe4f638d40f7af02f7d4e61c4--terraform-1.5.7.bottle_manifest.json
==> Fetching terraform
==> Downloading https://ghcr.io/v2/homebrew/core/terraform/blobs/sha256:f43afa7c6970e1bc768f739829ee589e88fd2b9275f867c5d0be60369ce0772e
Already downloaded: /Users/spice/Library/Caches/Homebrew/downloads/035ebdf8caeb70e899395805af7e655cf61fcda92aaffd3f96172667b2e19081--terraform--1.5.7.arm64_sonoma.bottle.tar.gz
==> Pouring terraform--1.5.7.arm64_sonoma.bottle.tar.gz
🍺  /opt/homebrew/Cellar/terraform/1.5.7: 6 files, 69.7MB
==> Running `brew cleanup terraform`...
Disable this behaviour by setting HOMEBREW_NO_INSTALL_CLEANUP.
Hide these hints with HOMEBREW_NO_ENV_HINTS (see `man brew`).

[amancevice]

The workaround is to install with an abs path:

brew install --formula /opt/homebrew/Library/Taps/hashicorp/homebrew-tap/Formula/terraform.rb

or checkout 4.1.20:

cd /opt/homebrew
git checkout 4.1.20