Improve updating behaviour

- Rename use of "preinstall" to "auto update". The original "preinstall"
  naming came from the fact that we used to only auto-update before
  `brew install` but now that it's many commands: this is more confusing
  than useful.
- Add `HOMEBREW_NO_UPDATE_REPORT_ONLY_INSTALLED` and remove
  `HOMEBREW_UPDATE_REPORT_ONLY_INSTALLED`; the latter is now the default
  and the prior provides an opt-out for better output, performance and
  avoiding reading potentially untrusted formulae.
- Add `HOMEBREW_UPDATE_FORMULA_VERSION_CHECKS` and don't check formula
  versions by default for better performance by default.

Co-authored-by: Eric Knibbe <3324775+EricFromCanada@users.noreply.github.com>
Co-authored-by: Sam Ford <1584702+samford@users.noreply.github.com>

Library/Homebrew/brew.sh

@@ -226,13 +226,13 @@ EOS
   fi
 }
 
-# Let user know we're still updating Homebrew if brew update --preinstall
+# Let user know we're still updating Homebrew if brew update --auto-update
 # exceeds 3 seconds.
-update-preinstall-timer() {
+auto-update-timer() {
   sleep 3
   # Outputting a command but don't want to run it, hence single quotes.
   # shellcheck disable=SC2016
-  echo 'Running `brew update --preinstall`...' >&2
+  echo 'Running `brew update --auto-update`...' >&2
   if [[ -z "${HOMEBREW_NO_ENV_HINTS}" && -z "${HOMEBREW_AUTO_UPDATE_SECS}" ]]
   then
     # shellcheck disable=SC2016
@@ -244,11 +244,11 @@ update-preinstall-timer() {
 
 # These variables are set from various Homebrew scripts.
 # shellcheck disable=SC2154
-update-preinstall() {
+auto-update() {
   [[ -z "${HOMEBREW_HELP}" ]] || return
   [[ -z "${HOMEBREW_NO_AUTO_UPDATE}" ]] || return
   [[ -z "${HOMEBREW_AUTO_UPDATING}" ]] || return
-  [[ -z "${HOMEBREW_UPDATE_PREINSTALL}" ]] || return
+  [[ -z "${HOMEBREW_UPDATE_AUTO}" ]] || return
   [[ -z "${HOMEBREW_AUTO_UPDATE_CHECKED}" ]] || return
 
   # If we've checked for updates, we don't need to check again.
@@ -280,11 +280,11 @@ update-preinstall() {
 
     if [[ -z "${HOMEBREW_VERBOSE}" ]]
     then
-      update-preinstall-timer &
+      auto-update-timer &
       timer_pid=$!
     fi
 
-    brew update --preinstall
+    brew update --auto-update
 
     if [[ -n "${timer_pid}" ]]
     then
@@ -842,7 +842,7 @@ then
   source "${HOMEBREW_BASH_COMMAND}"
 
   {
-    update-preinstall "$@"
+    auto-update "$@"
     "homebrew-${HOMEBREW_COMMAND}" "$@"
     exit $?
   }
@@ -856,7 +856,7 @@ else
   # HOMEBREW_RUBY_PATH set by utils/ruby.sh
   # shellcheck disable=SC2154
   {
-    update-preinstall "$@"
+    auto-update "$@"
     exec "${HOMEBREW_RUBY_PATH}" "${HOMEBREW_RUBY_WARNINGS}" "${RUBY_DISABLE_OPTIONS}" \
       "${HOMEBREW_LIBRARY}/Homebrew/brew.rb" "$@"
   }

Library/Homebrew/cmd/update-report.rb

@@ -16,9 +16,9 @@ module Homebrew
 
   module_function
 
-  def update_preinstall_header(args:)
-    @update_preinstall_header ||= begin
-      ohai "Auto-updated Homebrew!" if args.preinstall?
+  def auto_update_header(args:)
+    @auto_update_header ||= begin
+      ohai "Auto-updated Homebrew!" if args.auto_update?
       true
     end
   end
@@ -29,7 +29,7 @@ def update_report_args
       description <<~EOS
         The Ruby implementation of `brew update`. Never called manually.
       EOS
-      switch "--preinstall",
+      switch "--auto-update", "--preinstall",
              description: "Run in 'auto-update' mode (faster, less output)."
       switch "-f", "--force",
              description: "Treat installed and updated formulae as if they are from "\
@@ -79,7 +79,7 @@ def output_update_report
       FileUtils.rm_f HOMEBREW_LOCKS/"update"
 
       update_args = []
-      update_args << "--preinstall" if args.preinstall?
+      update_args << "--auto-update" if args.auto_update?
       update_args << "--force" if args.force?
       exec HOMEBREW_BREW_FILE, "update", *update_args
     end
@@ -123,7 +123,7 @@ def output_update_report
     odie "update-report should not be called directly!" if initial_revision.empty? || current_revision.empty?
 
     if initial_revision != current_revision
-      update_preinstall_header args: args
+      auto_update_header args: args
 
       updated = true
 
@@ -150,7 +150,7 @@ def output_update_report
     updated_taps = []
     Tap.each do |tap|
       next unless tap.git?
-      next if (tap.core_tap? || tap == "homebrew/cask") && Homebrew::EnvConfig.install_from_api? && args.preinstall?
+      next if (tap.core_tap? || tap == "homebrew/cask") && Homebrew::EnvConfig.install_from_api? && args.auto_update?
 
       if ENV["HOMEBREW_MIGRATE_LINUXBREW_FORMULAE"].present? && tap.core_tap? &&
          Settings.read("linuxbrewmigrated") != "true"
@@ -182,12 +182,12 @@ def output_update_report
       end
       if reporter.updated?
         updated_taps << tap.name
-        hub.add(reporter, preinstall: args.preinstall?)
+        hub.add(reporter, auto_update: args.auto_update?)
       end
     end
 
     unless updated_taps.empty?
-      update_preinstall_header args: args
+      auto_update_header args: args
       puts "Updated #{updated_taps.count} #{"tap".pluralize(updated_taps.count)} (#{updated_taps.to_sentence})."
       updated = true
     end
@@ -196,7 +196,12 @@ def output_update_report
       if hub.empty?
         puts "No changes to formulae." unless args.quiet?
       else
-        hub.dump(updated_formula_report: !args.preinstall?) unless args.quiet?
+        if ENV.fetch("HOMEBREW_UPDATE_REPORT_ONLY_INSTALLED", false)
+          opoo "HOMEBREW_UPDATE_REPORT_ONLY_INSTALLED is now the default behaviour, " \
+               "so you can unset it from your environment."
+        end
+
+        hub.dump(updated_formula_report: !args.auto_update?) unless args.quiet?
         hub.reporters.each(&:migrate_tap_migration)
         hub.reporters.each { |r| r.migrate_formula_rename(force: args.force?, verbose: args.verbose?) }
         CacheStoreDatabase.use(:descriptions) do |db|
@@ -208,7 +213,7 @@ def output_update_report
                                    .update_from_report!(hub)
         end
 
-        if !args.preinstall? && !args.quiet?
+        if !args.auto_update? && !args.quiet?
           outdated_formulae = Formula.installed.count(&:outdated?)
           outdated_casks = Cask::Caskroom.casks.count(&:outdated?)
           update_pronoun = if (outdated_formulae + outdated_casks) == 1
@@ -234,8 +239,8 @@ def output_update_report
           end
         end
       end
-      puts if args.preinstall?
-    elsif !args.preinstall? && !ENV["HOMEBREW_UPDATE_FAILED"] && !ENV["HOMEBREW_MIGRATE_LINUXBREW_FORMULAE"]
+      puts if args.auto_update?
+    elsif !args.auto_update? && !ENV["HOMEBREW_UPDATE_FAILED"] && !ENV["HOMEBREW_MIGRATE_LINUXBREW_FORMULAE"]
       puts "Already up-to-date." unless args.quiet?
     end
 
@@ -326,7 +331,7 @@ def initialize(tap)
     raise ReporterRevisionUnsetError, current_revision_var if @current_revision.empty?
   end
 
-  def report(preinstall: false)
+  def report(auto_update: false)
     return @report if @report
 
     @report = Hash.new { |h, k| h[k] = [] }
@@ -364,8 +369,8 @@ def report(preinstall: false)
       when "M"
         name = tap.formula_file_to_name(src)
 
-        # Skip reporting updated formulae to speed up automatic updates.
-        if preinstall
+        # Skip reporting updated formulae by default (as it's slow).
+        unless Homebrew::EnvConfig.update_formula_version_checks?
           @report[:M] << name
           next
         end
@@ -570,9 +575,9 @@ def select_formula(key)
     @hash.fetch(key, [])
   end
 
-  def add(reporter, preinstall: false)
+  def add(reporter, auto_update: false)
     @reporters << reporter
-    report = reporter.report(preinstall: preinstall).delete_if { |_k, v| v.empty? }
+    report = reporter.report(auto_update: auto_update).delete_if { |_k, v| v.empty? }
     @hash.update(report) { |_key, oldval, newval| oldval.concat(newval) }
   end
 
@@ -603,7 +608,7 @@ def dump(updated_formula_report: true)
   private
 
   def dump_formula_report(key, title)
-    only_installed = Homebrew::EnvConfig.update_report_only_installed?
+    only_installed = !Homebrew::EnvConfig.no_update_report_only_installed?
 
     formulae = select_formula(key).sort.map do |name, new_name|
       # Format list items of renamed formulae

Library/Homebrew/cmd/update.sh

@@ -3,7 +3,7 @@
 #:  Fetch the newest version of Homebrew and all formulae from GitHub using `git`(1) and perform any necessary migrations.
 #:
 #:        --merge                      Use `git merge` to apply updates (rather than `git rebase`).
-#:        --preinstall                 Run on auto-updates (e.g. before `brew install`). Skips some slower steps.
+#:        --auto-update                Run on auto-updates (e.g. before `brew install`). Skips some slower steps.
 #:    -f, --force                      Always do a slower, full update check (even if unnecessary).
 #:    -q, --quiet                      Make some output more quiet
 #:    -v, --verbose                    Print the directories checked and `git` operations performed.
@@ -337,7 +337,7 @@ homebrew-update() {
       --merge) HOMEBREW_MERGE=1 ;;
       --force) HOMEBREW_UPDATE_FORCE=1 ;;
       --simulate-from-current-branch) HOMEBREW_SIMULATE_FROM_CURRENT_BRANCH=1 ;;
-      --preinstall) export HOMEBREW_UPDATE_PREINSTALL=1 ;;
+      --auto-update) export HOMEBREW_UPDATE_AUTO=1 ;;
       --*) ;;
       -*)
         [[ "${option}" == *v* ]] && HOMEBREW_VERBOSE=1
@@ -547,7 +547,7 @@ EOS
   for DIR in "${HOMEBREW_REPOSITORY}" "${HOMEBREW_LIBRARY}"/Taps/*/*
   do
     if [[ -n "${HOMEBREW_INSTALL_FROM_API}" ]] &&
-       [[ -n "${HOMEBREW_UPDATE_PREINSTALL}" ]] &&
+       [[ -n "${HOMEBREW_UPDATE_AUTO}" ]] &&
        [[ "${DIR}" == "${HOMEBREW_CORE_REPOSITORY}" ]]
     then
       continue
@@ -591,7 +591,7 @@ EOS
     (
       UPSTREAM_REPOSITORY_URL="$(git config remote.origin.url)"
 
-      # HOMEBREW_UPDATE_FORCE and HOMEBREW_UPDATE_PREINSTALL aren't modified here so ignore subshell warning.
+      # HOMEBREW_UPDATE_FORCE and HOMEBREW_UPDATE_AUTO aren't modified here so ignore subshell warning.
       # shellcheck disable=SC2030
       if [[ "${UPSTREAM_REPOSITORY_URL}" == "https://github.com/"* ]]
       then
@@ -630,7 +630,7 @@ EOS
         # Touch FETCH_HEAD to confirm we've checked for an update.
         [[ -f "${DIR}/.git/FETCH_HEAD" ]] && touch "${DIR}/.git/FETCH_HEAD"
         [[ -z "${HOMEBREW_UPDATE_FORCE}" ]] && [[ "${UPSTREAM_SHA_HTTP_CODE}" == "304" ]] && exit
-      elif [[ -n "${HOMEBREW_UPDATE_PREINSTALL}" ]]
+      elif [[ -n "${HOMEBREW_UPDATE_AUTO}" ]]
       then
         FORCE_AUTO_UPDATE="$(git config homebrew.forceautoupdate 2>/dev/null || echo "false")"
         if [[ "${FORCE_AUTO_UPDATE}" != "true" ]]
@@ -650,7 +650,7 @@ EOS
       local tmp_failure_file="${HOMEBREW_REPOSITORY}/.git/TMP_FETCH_FAILURES"
       rm -f "${tmp_failure_file}"
 
-      if [[ -n "${HOMEBREW_UPDATE_PREINSTALL}" ]]
+      if [[ -n "${HOMEBREW_UPDATE_AUTO}" ]]
       then
         git fetch --tags --force "${QUIET_ARGS[@]}" origin \
           "refs/heads/${UPSTREAM_BRANCH_DIR}:refs/remotes/origin/${UPSTREAM_BRANCH_DIR}" 2>/dev/null
@@ -701,10 +701,10 @@ EOS
 
   for DIR in "${HOMEBREW_REPOSITORY}" "${HOMEBREW_LIBRARY}"/Taps/*/*
   do
-    # HOMEBREW_UPDATE_PREINSTALL wasn't modified in subshell.
+    # HOMEBREW_UPDATE_AUTO wasn't modified in subshell.
     # shellcheck disable=SC2031
     if [[ -n "${HOMEBREW_INSTALL_FROM_API}" ]] &&
-       [[ -n "${HOMEBREW_UPDATE_PREINSTALL}" ]] &&
+       [[ -n "${HOMEBREW_UPDATE_AUTO}" ]] &&
        [[ "${DIR}" == "${HOMEBREW_CORE_REPOSITORY}" ||
           "${DIR}" == "${HOMEBREW_LIBRARY}/Taps/homebrew/homebrew-cask" ]]
     then
@@ -747,7 +747,7 @@ EOS
 
   safe_cd "${HOMEBREW_REPOSITORY}"
 
-  # HOMEBREW_UPDATE_PREINSTALL wasn't modified in subshell.
+  # HOMEBREW_UPDATE_AUTO wasn't modified in subshell.
   # shellcheck disable=SC2031
   if [[ -n "${HOMEBREW_UPDATED}" ]] ||
      [[ -n "${HOMEBREW_UPDATE_FAILED}" ]] ||
@@ -756,11 +756,11 @@ EOS
      [[ -n "${HOMEBREW_MIGRATE_LINUXBREW_FORMULAE}" ]] ||
      [[ -d "${HOMEBREW_LIBRARY}/LinkedKegs" ]] ||
      [[ ! -f "${HOMEBREW_CACHE}/all_commands_list.txt" ]] ||
-     [[ -n "${HOMEBREW_DEVELOPER}" && -z "${HOMEBREW_UPDATE_PREINSTALL}" ]]
+     [[ -n "${HOMEBREW_DEVELOPER}" && -z "${HOMEBREW_UPDATE_AUTO}" ]]
   then
     brew update-report "$@"
     return $?
-  elif [[ -z "${HOMEBREW_UPDATE_PREINSTALL}" && -z "${HOMEBREW_QUIET}" ]]
+  elif [[ -z "${HOMEBREW_UPDATE_AUTO}" && -z "${HOMEBREW_QUIET}" ]]
   then
     echo "Already up-to-date."
   fi

Library/Homebrew/env_config.rb

@@ -289,6 +289,10 @@ module EnvConfig
                      "outdated.",
         boolean:     true,
       },
+      HOMEBREW_NO_UPDATE_REPORT_ONLY_INSTALLED:  {
+        description: "If set, `brew update` lists updates to all software.",
+        boolean:     true,
+      },
       HOMEBREW_PRY:                              {
         description: "If set, use Pry for the `brew irb` command.",
         boolean:     true,
@@ -325,8 +329,9 @@ module EnvConfig
         default_text: "macOS: `/private/tmp`, Linux: `/tmp`.",
         default:      HOMEBREW_DEFAULT_TEMP,
       },
-      HOMEBREW_UPDATE_REPORT_ONLY_INSTALLED:     {
-        description: "If set, `brew update` only lists updates to installed software.",
+      HOMEBREW_UPDATE_FORMULA_VERSION_CHECKS:    {
+        description: "If set, `brew update` only lists updates to formulae with differing versions. " \
+                     "Note this is slower than the default behaviour.",
         boolean:     true,
       },
       HOMEBREW_UPDATE_TO_TAG:                    {

Library/Homebrew/test/completions_spec.rb

@@ -195,13 +195,13 @@ def delete_completions_setting(setting: "linkcompletions")
 
       it "returns an array of options for a shell command" do
         expected_options = {
-          "--debug"      => "Display a trace of all shell commands as they are executed.",
-          "--force"      => "Always do a slower, full update check (even if unnecessary).",
-          "--help"       => "Show this message.",
-          "--merge"      => "Use `git merge` to apply updates (rather than `git rebase`).",
-          "--preinstall" => "Run on auto-updates (e.g. before `brew install`). Skips some slower steps.",
-          "--quiet"      => "Make some output more quiet",
-          "--verbose"    => "Print the directories checked and `git` operations performed.",
+          "--auto-update" => "Run on auto-updates (e.g. before `brew install`). Skips some slower steps.",
+          "--debug"       => "Display a trace of all shell commands as they are executed.",
+          "--force"       => "Always do a slower, full update check (even if unnecessary).",
+          "--help"        => "Show this message.",
+          "--merge"       => "Use `git merge` to apply updates (rather than `git rebase`).",
+          "--quiet"       => "Make some output more quiet",
+          "--verbose"     => "Print the directories checked and `git` operations performed.",
         }
         expect(described_class.command_options("update")).to eq expected_options
       end
@@ -277,11 +277,11 @@ def delete_completions_setting(setting: "linkcompletions")
             case "${cur}" in
               -*)
                 __brewcomp "
+                --auto-update
                 --debug
                 --force
                 --help
                 --merge
-                --preinstall
                 --quiet
                 --verbose
                 "
@@ -342,11 +342,11 @@ def delete_completions_setting(setting: "linkcompletions")
           # brew update
           _brew_update() {
             _arguments \\
+              '--auto-update[Run on auto-updates (e.g. before `brew install`). Skips some slower steps]' \\
               '--debug[Display a trace of all shell commands as they are executed]' \\
               '--force[Always do a slower, full update check (even if unnecessary)]' \\
               '--help[Show this message]' \\
               '--merge[Use `git merge` to apply updates (rather than `git rebase`)]' \\
-              '--preinstall[Run on auto-updates (e.g. before `brew install`). Skips some slower steps]' \\
               '--quiet[Make some output more quiet]' \\
               '--verbose[Print the directories checked and `git` operations performed]'
           }
@@ -402,11 +402,11 @@ def delete_completions_setting(setting: "linkcompletions")
         completion = described_class.generate_fish_subcommand_completion("update")
         expect(completion).to eq <<~COMPLETION
           __fish_brew_complete_cmd 'update' 'Fetch the newest version of Homebrew and all formulae from GitHub using `git`(1) and perform any necessary migrations'
+          __fish_brew_complete_arg 'update' -l auto-update -d 'Run on auto-updates (e.g. before `brew install`). Skips some slower steps'
           __fish_brew_complete_arg 'update' -l debug -d 'Display a trace of all shell commands as they are executed'
           __fish_brew_complete_arg 'update' -l force -d 'Always do a slower, full update check (even if unnecessary)'
           __fish_brew_complete_arg 'update' -l help -d 'Show this message'
           __fish_brew_complete_arg 'update' -l merge -d 'Use `git merge` to apply updates (rather than `git rebase`)'
-          __fish_brew_complete_arg 'update' -l preinstall -d 'Run on auto-updates (e.g. before `brew install`). Skips some slower steps'
           __fish_brew_complete_arg 'update' -l quiet -d 'Make some output more quiet'
           __fish_brew_complete_arg 'update' -l verbose -d 'Print the directories checked and `git` operations performed'
         COMPLETION