Strict audit does not check for `env :std` for formulae in the core tap

[dunkmann00]

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• ran brew update and can still reproduce the problem?
• ran brew doctor, fixed all issues and can still reproduce the problem?
• ran brew config and brew doctor and included their output with your issue?

What you were trying to do (and why)

Running brew audit --new-formula on a formula I am working on resulted in a completion with no errors. After trying to submit this formula I was told having env :std is not allowed. After then trying to find some documentation to get more info on this I learned that it is deprecated (#1775) and also that it is something that a strict audit (which is one of the flags that is set with --new-formula) should have reported.

What happened (include command output)

The audit completed for my formula with no errors.

Command output

~ % brew audit --new-formula gcc-arm-embedded

~ %

What you expected to happen

The audit should have failed and shown a message that env :std is not allowed in a core formula.

~ % brew audit --new-formula gcc-arm-embedded
gcc-arm-embedded:
  * `env :std` in `core` formulae is deprecated
Error: 1 problem in 1 formula detected
~ %

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

brew audit --new-formula gcc-arm-embedded

-or-

brew audit --strict gcc-arm-embedded

Additional

After looking into this, I think it is just a simple problem with the logic flow of the function that performs line audits.

The excerpt below is from def line_problems(line, _lineno) and in it, on line 951, if the regex doesn't find anything it returns. But then the code below it, which includes the env :std check, will never be reached.

brew/Library/Homebrew/dev-cmd/audit.rb

Lines 947 to 960 in 930bbe0

	if !@core_tap && line =~ /depends_on .+ if build\.with(out)?\?\(?["']\w+["']\)?/
	problem "`Use :optional` or `:recommended` instead of `#{Regexp.last_match(0)}`"
	end
	return unless line =~ %r{share(\s*[/+]\s*)(['"])#{Regexp.escape(formula.name)}(?:\2|/)}
	problem "Use pkgshare instead of (share#{Regexp.last_match(1)}\"#{formula.name}\")"
	return unless @core_tap
	return unless line.include?("env :std")
	problem "`env :std` in `core` formulae is deprecated"
	end

I have created a pull request that I believe fixes the problem. I'll link it to this issue once I get it setup.

brew config - output

HOMEBREW_VERSION: 2.1.16-62-g6e70c4e
ORIGIN: https://github.com/Homebrew/brew
HEAD: 6e70c4efcd1264bff570ed3b25dc608af9e4450a
Last commit: 48 minutes ago
Core tap ORIGIN: https://github.com/Homebrew/homebrew-core
Core tap HEAD: b99a095
Core tap last commit: 2 hours ago
HOMEBREW_PREFIX: /usr/local
HOMEBREW_DEV_CMD_RUN: 1
CPU: dodeca-core 64-bit kabylake
Homebrew Ruby: 2.6.3 => /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/bin/ruby
Clang: 11.0 build 1100
Git: 2.21.0 => /Library/Developer/CommandLineTools/usr/bin/git
Curl: 7.64.1 => /usr/bin/curl
macOS: 10.15.1-x86_64
CLT: 11.2.0.0.1.1571444319
Xcode: 11.2
CLT headers: 11.2.0.0.1.1571444319

[jonchang]

Assuming this was fixed by #6738