Structured API bootstrap actions cannot access required formula resources

[fishcharlie]

brew doctor output

Your system is ready to brew.

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.
• I did not use AI/LLM to create this issue, or I disclosed the tool and model used; I will answer maintainer questions myself without AI/LLM.

brew config output

HOMEBREW_VERSION: 6.0.15-125-g7372067
ORIGIN: https://github.com/Homebrew/brew
HEAD: 73720671af9c86920d7baf090bfb4161765bb5ef
Last commit: 16 hours ago
Branch: main
Core tap: N/A
Core cask tap: N/A
HOMEBREW_PREFIX: /home/linuxbrew/.linuxbrew
HOMEBREW_CLEANUP_PERIODIC_FULL_DAYS: 3650
HOMEBREW_NO_AUTO_UPDATE: set
HOMEBREW_NO_ENV_HINTS: set
HOMEBREW_NO_SANDBOX_LINUX: set
Homebrew Ruby: 4.0.6 => /home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/vendor/portable-ruby/4.0.6/bin/ruby
CPU: dual-core 64-bit sapphirerapids
Clang: 18.1.3
Git: 2.54.0 => /bin/git
Curl: 8.5.0 => /bin/curl
Kernel: Linux 6.17.0-1020-azure x86_64 GNU/Linux
Landlock ABI: 7
OS: Ubuntu 24.04.4 LTS (noble)
Host glibc: 2.39
Host libstdc++: 6.0.33
/usr/bin/gcc-13: 13.3.0
/usr/bin/ruby: 3.2.3
glibc: N/A
gcc@13: N/A
gcc: N/A
xorg: N/A

What were you trying to do (and why)?

I was validating that structured post-install actions work for formulas loaded from the Homebrew API after enabling developer mode and updating to Homebrew main. The specific formula below is only a minimal trigger; the reported failure is in the generic API-loaded structured-action path.

What happened (include all command output)?

Both updates completed successfully, and brew doctor reported a clean system:

$ brew update
Already up-to-date.
$ brew update
Already up-to-date.
$ brew doctor
Your system is ready to brew.

The API formula data declares a structured bootstrap_cpython post-install action but provides no resources:

{
  "versions": {
    "stable": "3.11.15",
    "bottle": true
  },
  "revision": 4,
  "tap_git_head": "7f32d96366933aa73ee5d2b17fed9015870f085f",
  "resources": null,
  "post_install_steps": [
    {
      "type": "bootstrap_cpython"
    }
  ]
}

The formula loads through Formulary::FromAPILoader, installs its bottle, and then its structured post-install action fails while looking up a resource that is absent from the API-loaded formula:

$ brew install --debug --verbose python@3.11
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FromAPILoader): loading python@3.11
...
Warning: The post-install step did not complete successfully
You can try again using:
  brew postinstall python@3.11
==> An exception occurred within a child process:
  ResourceMissingError: python@3.11 does not define resource "setuptools"

/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/software_spec.rb:204:in 'block in SoftwareSpec#resource'
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/software_spec.rb:204:in 'Hash#fetch'
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/software_spec.rb:204:in 'SoftwareSpec#resource'
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/formula.rb:867:in 'Formula#resource'
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/install_steps/formula_actions.rb:226:in 'Homebrew::InstallSteps::Runner#run_bootstrap_cpython'
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/install_steps.rb:1038:in 'Homebrew::InstallSteps::Runner#run_install_step'
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/install_steps.rb:876:in 'block in Homebrew::InstallSteps::Runner#run'
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/install_steps.rb:872:in 'Array#each'
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/install_steps.rb:872:in 'Homebrew::InstallSteps::Runner#run'
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/formula.rb:1611:in 'block in Formula#run_post_install_steps'
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/formula.rb:1610:in 'Formula#run_post_install_steps'

Retrying brew postinstall --debug --verbose python@3.11 produces the same ResourceMissingError.

What did you expect to happen?

An API-loaded structured bootstrap action should have access to every formula resource it requires, or the API representation should contain enough information for the action to execute. The post-install action should complete successfully.

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

On a clean Ubuntu 24.04 GitHub-hosted runner with current stable Homebrew installed:

brew developer on
brew update
brew update
brew doctor
brew config
brew install --debug --verbose python@3.11
brew postinstall --debug --verbose python@3.11

---

This issue was generated with the assistance of OpenAI Codex (GPT-5.6 Sol). I reviewed and verified the reproduction and will answer maintainer follow-up questions myself without AI/LLM assistance.

[github-actions]

Thanks for your issue. This has been closed because it appears to use an incomplete or outdated issue template.

Please edit this issue to restore the following sections and checkboxes from the current issue template (you do not need to tick the checkboxes):

• ### Step-by-step reproduction instructions (running brew commands) section
• 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.
• I did not use AI/LLM to create this issue, or I disclosed the tool and model used; I will answer maintainer questions myself without AI/LLM.

This workflow will reopen this issue automatically once they are present. Do not create a new issue for this.