dev-cmd/unbottled: add --lost option

This option tries to find bottles where the bottle was removed
from the formula in the past week and not added back in.

It checks the output of `git log` to see if there are any
bottles that fit this criteria.

Library/Homebrew/dev-cmd/unbottled.rb

@@ -21,11 +21,13 @@ module Homebrew
              description: "Skip getting analytics data and sort by number of dependents instead."
       switch "--total",
              description: "Print the number of unbottled and total formulae."
+      switch "--lost",
+             description: "Print the `homebrew/core` commits where bottles were lost in the last week."
       switch "--eval-all",
              description: "Evaluate all available formulae and casks, whether installed or not, to check them. " \
                           "Implied if `HOMEBREW_EVAL_ALL` is set."
 
-      conflicts "--dependents", "--total"
+      conflicts "--dependents", "--total", "--lost"
 
       named_args :formula
     end
@@ -43,6 +45,17 @@ module Homebrew
       Utils::Bottles.tag
     end
 
+    if args.lost?
+      if args.named.present?
+        raise UsageError, "`brew unbottled --lost` cannot be used with formula arguments!"
+      elsif !CoreTap.instance.installed?
+        raise UsageError, "`brew unbottled --lost` requires `homebrew/core` to be tapped locally!"
+      else
+        output_lost_bottles
+        return
+      end
+    end
+
     os = @bottle_tag.system
     arch = if Hardware::CPU::INTEL_ARCHS.include?(@bottle_tag.arch)
       :intel
@@ -243,4 +256,53 @@ module Homebrew
 
     puts "No unbottled dependencies found!"
   end
+
+  def output_lost_bottles
+    # $ git log --patch -G\^\ \+sha256.\*\ sonoma: --since=@\{\'1\ week\ ago\'\}
+    git_log = %w[git log --patch]
+    git_log << "-G^ +sha256.* #{@bottle_tag}:"
+    git_log << "--since=@{'1 week ago'}"
+
+    bottle_tag_sha_regex = /^[+-] +sha256.* #{@bottle_tag}: /
+
+    processed_formulae = Set.new
+    commit = T.let(nil, T.nilable(String))
+    formula = T.let(nil, T.nilable(String))
+    lost_bottles = 0
+
+    CoreTap.instance.path.cd do
+      Utils.safe_popen_read(*git_log) do |io|
+        io.each_line do |line|
+          case line
+          when /^commit [0-9a-f]{40}$/
+            # Example match: `commit 7289b409b96a752540befef1a56b8a818baf1db7`
+            if commit && lost_bottles.positive? && processed_formulae.exclude?(formula)
+              puts "#{commit}: bottle lost for #{formula}"
+            end
+            processed_formulae << formula
+            commit = line.split.last
+            lost_bottles = 0
+          when %r{^diff --git a/Formula/}
+            # Example match: `diff --git a/Formula/a/aws-cdk.rb b/Formula/a/aws-cdk.rb`
+            formula = line.split("/").last.chomp(".rb\n")
+          when bottle_tag_sha_regex
+            # Example match: `-    sha256 cellar: :any_skip_relocation, sonoma: "f0a4..."`
+            next if processed_formulae.include?(formula)
+
+            case line.chr
+            when "+" then lost_bottles -= 1
+            when "-" then lost_bottles += 1
+            end
+          when /^[+] +sha256.* all: /
+            # Example match: `+    sha256 cellar: :any_skip_relocation, all: "9e35..."`
+            lost_bottles -= 1
+          end
+        end
+      end
+    end
+
+    return if !commit || !lost_bottles.positive? || processed_formulae.include?(formula)
+
+    puts "#{commit}: bottle lost for #{formula}"
+  end
 end

completions/bash/brew

@@ -2258,6 +2258,7 @@ _brew_unbottled() {
       --dependents
       --eval-all
       --help
+      --lost
       --quiet
       --tag
       --total

completions/fish/brew.fish

@@ -1500,6 +1500,7 @@ __fish_brew_complete_arg 'unbottled' -l debug -d 'Display any debugging informat
 __fish_brew_complete_arg 'unbottled' -l dependents -d 'Skip getting analytics data and sort by number of dependents instead'
 __fish_brew_complete_arg 'unbottled' -l eval-all -d 'Evaluate all available formulae and casks, whether installed or not, to check them. Implied if `HOMEBREW_EVAL_ALL` is set'
 __fish_brew_complete_arg 'unbottled' -l help -d 'Show this message'
+__fish_brew_complete_arg 'unbottled' -l lost -d 'Print the `homebrew/core` commits where bottles were lost in the last week'
 __fish_brew_complete_arg 'unbottled' -l quiet -d 'Make some output more quiet'
 __fish_brew_complete_arg 'unbottled' -l tag -d 'Use the specified bottle tag (e.g. `big_sur`) instead of the current OS'
 __fish_brew_complete_arg 'unbottled' -l total -d 'Print the number of unbottled and total formulae'

completions/zsh/_brew

@@ -1846,12 +1846,13 @@ _brew_typecheck() {
 _brew_unbottled() {
   _arguments \
     '--debug[Display any debugging information]' \
-    '(--total)--dependents[Skip getting analytics data and sort by number of dependents instead]' \
+    '(--total --lost)--dependents[Skip getting analytics data and sort by number of dependents instead]' \
     '--eval-all[Evaluate all available formulae and casks, whether installed or not, to check them. Implied if `HOMEBREW_EVAL_ALL` is set]' \
     '--help[Show this message]' \
+    '(--dependents --total)--lost[Print the `homebrew/core` commits where bottles were lost in the last week]' \
     '--quiet[Make some output more quiet]' \
     '--tag[Use the specified bottle tag (e.g. `big_sur`) instead of the current OS]' \
-    '(--dependents)--total[Print the number of unbottled and total formulae]' \
+    '(--dependents --lost)--total[Print the number of unbottled and total formulae]' \
     '--verbose[Make some output more verbose]' \
     - formula \
     '*::formula:__brew_formulae'

docs/Manpage.md

@@ -1626,6 +1626,8 @@ Show the unbottled dependents of formulae.
   Skip getting analytics data and sort by number of dependents instead.
 * `--total`:
   Print the number of unbottled and total formulae.
+* `--lost`:
+  Print the `homebrew/core` commits where bottles were lost in the last week.
 * `--eval-all`:
   Evaluate all available formulae and casks, whether installed or not, to check them. Implied if `HOMEBREW_EVAL_ALL` is set.
 

manpages/brew.1

@@ -2339,6 +2339,10 @@ Skip getting analytics data and sort by number of dependents instead\.
 Print the number of unbottled and total formulae\.
 .
 .TP
+\fB\-\-lost\fR
+Print the \fBhomebrew/core\fR commits where bottles were lost in the last week\.
+.
+.TP
 \fB\-\-eval\-all\fR
 Evaluate all available formulae and casks, whether installed or not, to check them\. Implied if \fBHOMEBREW_EVAL_ALL\fR is set\.
 .