Installing a cask from a custom tap fails with a trust error if it `conflicts_with` another third-party cask

[gerlero]

brew doctor output

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Warning: /usr/bin occurs before /opt/homebrew/bin in your PATH.
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provided by Homebrew. Consider setting your PATH so that
/opt/homebrew/bin occurs before /usr/bin. Here is a one-liner:
  echo 'export PATH="/opt/homebrew/bin:$PATH"' >> ~/.zshrc

The following tools exist at both paths:
  openssl

Warning: Broken symlinks were found. Remove them with `brew cleanup`:
  /opt/homebrew/etc/bash_completion.d/docker-compose
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Verification

• I ran brew update twice and am still able to reproduce my issue.
• My "brew doctor output" above says Your system is ready to brew or a definitely unrelated Tier message.
• 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: 6.0.9-17-ga34c4ca
ORIGIN: https://github.com/Homebrew/brew
HEAD: a34c4cad0b2ebf21046b892739139539328ea3fb
Last commit: 2 hours ago
Branch: main
Core tap: N/A
Core cask tap: N/A
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_DOWNLOAD_CONCURRENCY: 16
HOMEBREW_FORBID_PACKAGES_FROM_PATHS: set
HOMEBREW_MAKE_JOBS: 8
HOMEBREW_REQUIRE_TAP_TRUST: set
Homebrew Ruby: 4.0.5 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/4.0.5_1/bin/ruby
CPU: octa-core 64-bit arm_ibiza
Clang: 21.0.0 build 2100
Git: 2.50.1 => /Library/Developer/CommandLineTools/usr/bin/git
Curl: 8.7.1 => /usr/bin/curl
macOS: 26.5.1-arm64
CLT: 26.6.0.0.1781586589
Xcode: N/A
Rosetta 2: false

What were you trying to do (and why)?

Trying to install a third-party cask from a custom tap using the fully qualified name to avoid having to trust it manually (but the cask itself declares a conflicts_with another cask on that custom tap)

What happened (include all command output)?

brew install gerlero/openfoam/openfoam

==> Trusted cask gerlero/openfoam/openfoam
==> Would install 1 cask:
gerlero/openfoam/openfoam
==> Fetching downloads for: gerlero/openfoam/openfoam
Error: Refusing to load cask gerlero/openfoam/openfoam@2606 from untrusted tap gerlero/openfoam.
Run `brew trust --cask gerlero/openfoam/openfoam@2606` or `brew trust gerlero/openfoam` to trust it.

Note: gerlero/openfoam/openfoam is the cask I want to install, and gerlero/openfoam/openfoam@2606 is a conflicts_with of the first, which is not installed, definitely should not be installed (that would cause the conflict!), and thus I should not need to manually trust it here nor do I think it should cause an error because of being untrusted.

What did you expect to happen?

Just trust and install the third-party cask I requested. The fact that another cask it conflicts_with is itself untrusted should not matter here.

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

brew install gerlero/openfoam/openfoam