output: express environment variables consistently

Library/Homebrew/bundle/commands/exec.rb

@@ -180,7 +180,7 @@ module Homebrew
               <<~EOS
                 Your shell has been configured to use a build environment from your `Brewfile`.
                 This should help you build stuff.
-                Hide these hints with HOMEBREW_NO_ENV_HINTS (see `man brew`).
+                Hide these hints with `HOMEBREW_NO_ENV_HINTS=1` (see `man brew`).
                 When done, type `exit`.
               EOS
             end

Library/Homebrew/cask/cask.rb

@@ -32,7 +32,7 @@ module Cask
 
     def self.all(eval_all: false)
       if !eval_all && !Homebrew::EnvConfig.eval_all?
-        raise ArgumentError, "Cask::Cask#all cannot be used without `--eval-all` or HOMEBREW_EVAL_ALL"
+        raise ArgumentError, "Cask::Cask#all cannot be used without `--eval-all` or `HOMEBREW_EVAL_ALL=1`"
       end
 
       # Load core casks from tokens so they load from the API when the core cask is not tapped.

Library/Homebrew/cask/installer.rb

@@ -248,7 +248,7 @@ on_request: true)
 
       raise CaskError, <<~EOS
         Cask '#{@cask}' does not have a sha256 checksum defined and was not installed.
-        This means you have the #{Formatter.identifier("--require-sha")} option set, perhaps in your HOMEBREW_CASK_OPTS.
+        This means you have the #{Formatter.identifier("--require-sha")} option set, perhaps in your `$HOMEBREW_CASK_OPTS`.
       EOS
     end
 
@@ -703,9 +703,9 @@ on_request: true)
           dep_full_name = cask_or_formula.full_name
           error_message = "The installation of #{@cask} has a dependency #{dep_full_name}\n" \
                           "from the #{dep_tap} tap but #{owner} "
-          error_message << "has not allowed this tap in `HOMEBREW_ALLOWED_TAPS`" unless dep_tap.allowed_by_env?
+          error_message << "has not allowed this tap in `$HOMEBREW_ALLOWED_TAPS`" unless dep_tap.allowed_by_env?
           error_message << " and\n" if !dep_tap.allowed_by_env? && dep_tap.forbidden_by_env?
-          error_message << "has forbidden this tap in `HOMEBREW_FORBIDDEN_TAPS`" if dep_tap.forbidden_by_env?
+          error_message << "has forbidden this tap in `$HOMEBREW_FORBIDDEN_TAPS`" if dep_tap.forbidden_by_env?
           error_message << ".#{owner_contact}"
 
           raise CaskCannotBeInstalledError.new(@cask, error_message)
@@ -717,9 +717,9 @@ on_request: true)
 
       error_message = "The installation of #{@cask.full_name} has the tap #{cask_tap}\n" \
                       "but #{owner} "
-      error_message << "has not allowed this tap in `HOMEBREW_ALLOWED_TAPS`" unless cask_tap.allowed_by_env?
+      error_message << "has not allowed this tap in `$HOMEBREW_ALLOWED_TAPS`" unless cask_tap.allowed_by_env?
       error_message << " and\n" if !cask_tap.allowed_by_env? && cask_tap.forbidden_by_env?
-      error_message << "has forbidden this tap in `HOMEBREW_FORBIDDEN_TAPS`" if cask_tap.forbidden_by_env?
+      error_message << "has forbidden this tap in `$HOMEBREW_FORBIDDEN_TAPS`" if cask_tap.forbidden_by_env?
       error_message << ".#{owner_contact}"
 
       raise CaskCannotBeInstalledError.new(@cask, error_message)

Library/Homebrew/cleanup.rb

@@ -258,8 +258,8 @@ module Homebrew
       return if Homebrew::EnvConfig.no_env_hints?
       return if Homebrew::EnvConfig.no_install_cleanup?
 
-      puts "Disable this behaviour by setting HOMEBREW_NO_INSTALL_CLEANUP."
+      puts "Disable this behaviour by setting `HOMEBREW_NO_INSTALL_CLEANUP=1`."
-      puts "Hide these hints with HOMEBREW_NO_ENV_HINTS (see `man brew`)."
+      puts "Hide these hints with `HOMEBREW_NO_ENV_HINTS=1` (see `man brew`)."
     end
 
     def self.puts_no_install_cleanup_disable_message_if_not_already!
@@ -315,8 +315,8 @@ module Homebrew
         end
 
         if ENV["HOMEBREW_AUTOREMOVE"].present?
-          opoo "HOMEBREW_AUTOREMOVE is now a no-op as it is the default behaviour. " \
+          opoo "`$HOMEBREW_AUTOREMOVE` is now a no-op as it is the default behaviour. " \
-               "Set HOMEBREW_NO_AUTOREMOVE=1 to disable it."
+               "Set `HOMEBREW_NO_AUTOREMOVE=1` to disable it."
         end
         Cleanup.autoremove(dry_run: dry_run?) unless Homebrew::EnvConfig.no_autoremove?
 

Library/Homebrew/cmd/deps.rb

@@ -130,7 +130,7 @@ module Homebrew
             opoo <<~EOS
               `brew deps` is not the actual runtime dependencies because #{not_using_runtime_dependencies_reason}!
               This means dependencies may differ from a formula's declared dependencies.
-              Hide these hints with HOMEBREW_NO_ENV_HINTS (see `man brew`).
+              Hide these hints with `HOMEBREW_NO_ENV_HINTS=1` (see `man brew`).
             EOS
           end
 

Library/Homebrew/cmd/desc.rb

@@ -49,7 +49,7 @@ module Homebrew
 
         if search_type.present?
           if !args.eval_all? && Homebrew::EnvConfig.no_install_from_api?
-            raise UsageError, "`brew desc --search` needs `--eval-all` passed or `$HOMEBREW_EVAL_ALL` set!"
+            raise UsageError, "`brew desc --search` needs `--eval-all` passed or `HOMEBREW_EVAL_ALL=1` set!"
           end
 
           query = args.named.join(" ")

Library/Homebrew/cmd/gist-logs.rb

@@ -63,7 +63,9 @@ module Homebrew
           files["00.tap.out"] = { content: tap }
         end
 
-        odie "`brew gist-logs` requires HOMEBREW_GITHUB_API_TOKEN to be set!" if GitHub::API.credentials_type == :none
+        if GitHub::API.credentials_type == :none
+          odie "`brew gist-logs` requires `$HOMEBREW_GITHUB_API_TOKEN` to be set!"
+        end
 
         # Description formatted to work well as page title when viewing gist
         descr = if formula.core_formula?

Library/Homebrew/cmd/readall.rb

@@ -50,7 +50,7 @@ module Homebrew
 
           taps = if args.no_named?
             unless args.eval_all?
-              raise UsageError, "`brew readall` needs a tap or `--eval-all` passed or `$HOMEBREW_EVAL_ALL` set!"
+              raise UsageError, "`brew readall` needs a tap or `--eval-all` passed or `HOMEBREW_EVAL_ALL=1` set!"
             end
 
             Tap.installed

Library/Homebrew/cmd/search.rb

@@ -72,7 +72,7 @@ module Homebrew
 
         if args.desc?
           if !args.eval_all? && Homebrew::EnvConfig.no_install_from_api?
-            raise UsageError, "`brew search --desc` needs `--eval-all` passed or `$HOMEBREW_EVAL_ALL` set!"
+            raise UsageError, "`brew search --desc` needs `--eval-all` passed or `HOMEBREW_EVAL_ALL=1` set!"
           end
 
           Search.search_descriptions(string_or_regex, args)

Library/Homebrew/cmd/uninstall.rb

@@ -78,8 +78,8 @@ module Homebrew
         end
 
         if ENV["HOMEBREW_AUTOREMOVE"].present?
-          opoo "HOMEBREW_AUTOREMOVE is now a no-op as it is the default behaviour. " \
+          opoo "`$HOMEBREW_AUTOREMOVE` is now a no-op as it is the default behaviour. " \
-               "Set HOMEBREW_NO_AUTOREMOVE=1 to disable it."
+               "Set `HOMEBREW_NO_AUTOREMOVE=1` to disable it."
         end
         Cleanup.autoremove unless Homebrew::EnvConfig.no_autoremove?
       end

Library/Homebrew/cmd/update-report.rb

@@ -56,7 +56,7 @@ module Homebrew
 
           if Homebrew::EnvConfig.core_git_remote != HOMEBREW_CORE_DEFAULT_GIT_REMOTE
             opoo <<~EOS
-              HOMEBREW_CORE_GIT_REMOTE was set: #{Homebrew::EnvConfig.core_git_remote}.
+              `$HOMEBREW_CORE_GIT_REMOTE` was set: #{Homebrew::EnvConfig.core_git_remote}.
               It has been unset for the migration.
               You may need to change this from a linuxbrew-core mirror to a homebrew-core one.
 
@@ -66,7 +66,7 @@ module Homebrew
 
           if Homebrew::EnvConfig.bottle_domain != HOMEBREW_BOTTLE_DEFAULT_DOMAIN
             opoo <<~EOS
-              HOMEBREW_BOTTLE_DOMAIN was set: #{Homebrew::EnvConfig.bottle_domain}.
+              `$HOMEBREW_BOTTLE_DOMAIN` was set: #{Homebrew::EnvConfig.bottle_domain}.
               It has been unset for the migration.
               You may need to change this from a Linuxbrew package mirror to a Homebrew one.
 
@@ -412,9 +412,9 @@ module Homebrew
                                   !Homebrew::EnvConfig.automatically_set_no_install_from_api?
         return unless no_install_from_api_set
 
-        ohai "You have HOMEBREW_NO_INSTALL_FROM_API set"
+        ohai "You have `$HOMEBREW_NO_INSTALL_FROM_API` set"
         puts "Homebrew >=4.1.0 is dramatically faster and less error-prone when installing"
-        puts "from the JSON API. Please consider unsetting HOMEBREW_NO_INSTALL_FROM_API."
+        puts "from the JSON API. Please consider unsetting `$HOMEBREW_NO_INSTALL_FROM_API`."
         puts "This message will only be printed once."
         puts "\n\n"
 

Library/Homebrew/cmd/update-reset.sh

@@ -52,6 +52,8 @@ homebrew-update-reset() {
 
   if [[ -z "${REPOS[*]}" ]]
   then
+    # HOMEBREW_REPOSITORY is set by bin/brew
+    # shellcheck disable=SC2154
     REPOS+=("${HOMEBREW_REPOSITORY}" "${HOMEBREW_LIBRARY}"/Taps/*/*)
   fi
 
@@ -71,7 +73,7 @@ homebrew-update-reset() {
     echo
 
     ohai "Resetting ${DIR}..."
-    # HOMEBREW_* variables here may all set by bin/brew or the user
+    # HOMEBREW_* variables here may all be set by bin/brew or the user
     # shellcheck disable=SC2154
     if [[ "${DIR}" == "${HOMEBREW_REPOSITORY}" &&
        (-n "${HOMEBREW_UPDATE_TO_TAG}" ||

Library/Homebrew/cmd/update.sh

@@ -650,9 +650,9 @@ EOS
         if [[ -z "${HOMEBREW_NO_ENV_HINTS}" && -z "${HOMEBREW_AUTO_UPDATE_SECS}" ]]
         then
           # shellcheck disable=SC2016
-          echo 'Adjust how often this is run with HOMEBREW_AUTO_UPDATE_SECS or disable with' >&2
+          echo 'Adjust how often this is run with `$HOMEBREW_AUTO_UPDATE_SECS` or disable with' >&2
           # shellcheck disable=SC2016
-          echo 'HOMEBREW_NO_AUTO_UPDATE. Hide these hints with HOMEBREW_NO_ENV_HINTS (see `man brew`).' >&2
+          echo '`$HOMEBREW_NO_AUTO_UPDATE=1`. Hide these hints with `$HOMEBREW_NO_ENV_HINTS=1` (see `man brew`).' >&2
         fi
       else
         ohai 'Updating Homebrew...' >&2

Library/Homebrew/cmd/uses.rb

@@ -123,7 +123,7 @@ module Homebrew
           eval_all = args.eval_all?
 
           if !args.installed? && !eval_all
-            raise UsageError, "`brew uses` needs `--installed` or `--eval-all` passed or `$HOMEBREW_EVAL_ALL` set!"
+            raise UsageError, "`brew uses` needs `--installed` or `--eval-all` passed or `HOMEBREW_EVAL_ALL=1` set!"
           end
 
           if show_formulae_and_casks || args.formula?

Library/Homebrew/dev-cmd/audit.rb

@@ -143,7 +143,7 @@ module Homebrew
             unless eval_all
               # This odisabled should probably stick around indefinitely.
               odisabled "brew audit",
-                        "brew audit --eval-all or HOMEBREW_EVAL_ALL"
+                        "`brew audit --eval-all` or set `HOMEBREW_EVAL_ALL=1`"
             end
             no_named_args = true
             [

Library/Homebrew/dev-cmd/bump.rb

@@ -117,7 +117,7 @@ module Homebrew
           else
             raise UsageError,
                   "`brew bump` without named arguments needs `--installed` or `--eval-all` passed or " \
-                  "`$HOMEBREW_EVAL_ALL` set!"
+                  "`HOMEBREW_EVAL_ALL=1` set!"
           end
 
           if args.start_with

Library/Homebrew/dev-cmd/determine-test-runners.rb

@@ -22,7 +22,7 @@ module Homebrew
                env:         :eval_all
         switch "--dependents",
                description: "Determine runners for testing dependents. " \
-                            "Requires `--eval-all` or `$HOMEBREW_EVAL_ALL` to be set.",
+                            "Requires `--eval-all` or `HOMEBREW_EVAL_ALL=1` to be set.",
                depends_on:  "--eval-all"
 
         named_args max: 2

Library/Homebrew/dev-cmd/formula-analytics.rb

@@ -109,10 +109,10 @@ module Homebrew
 
         return if args.setup?
 
-        odie "HOMEBREW_NO_ANALYTICS is set!" if ENV["HOMEBREW_NO_ANALYTICS"]
+        odie "`$HOMEBREW_NO_ANALYTICS` is set!" if ENV["HOMEBREW_NO_ANALYTICS"]
 
         token = ENV.fetch("HOMEBREW_INFLUXDB_TOKEN", nil)
-        odie "No InfluxDB credentials found in HOMEBREW_INFLUXDB_TOKEN!" unless token
+        odie "No InfluxDB credentials found in `$HOMEBREW_INFLUXDB_TOKEN`!" unless token
 
         client = InfluxDBClient3.new(
           token:,
@@ -203,7 +203,7 @@ module Homebrew
             client.query(query:, language: "sql").to_batches
           rescue PyCall::PyError => e
             if e.message.include?("message: unauthenticated")
-              odie "Could not authenticate with InfluxDB! Please check your HOMEBREW_INFLUXDB_TOKEN!"
+              odie "Could not authenticate with InfluxDB! Please check your `$HOMEBREW_INFLUXDB_TOKEN`!"
             end
             raise
           end

Library/Homebrew/dev-cmd/pr-pull.rb

@@ -481,7 +481,7 @@ module Homebrew
 
           name = "#{tap.name}/#{File.basename(line.chomp, ".rb")}"
           if Homebrew::EnvConfig.disable_load_formula?
-            opoo "Can't check if updated bottles are necessary as HOMEBREW_DISABLE_LOAD_FORMULA is set!"
+            opoo "Can't check if updated bottles are necessary as `$HOMEBREW_DISABLE_LOAD_FORMULA` is set!"
             break
           end
           begin

Library/Homebrew/dev-cmd/sh.rb

@@ -55,7 +55,7 @@ module Homebrew
               gem and pip will ignore our configuration and insist on using the
               environment they were built under (mostly). Sadly, scons will also
               ignore our configuration.
-              Hide these hints with HOMEBREW_NO_ENV_HINTS (see `man brew`).
+              Hide these hints with `HOMEBREW_NO_ENV_HINTS=1` (see `man brew`).
               When done, type `exit`.
             EOS
           end

Library/Homebrew/dev-cmd/unbottled.rb

@@ -68,7 +68,7 @@ module Homebrew
           eval_all = args.eval_all?
 
           if args.total? && !eval_all
-            raise UsageError, "`brew unbottled --total` needs `--eval-all` passed or `$HOMEBREW_EVAL_ALL` set!"
+            raise UsageError, "`brew unbottled --total` needs `--eval-all` passed or `HOMEBREW_EVAL_ALL=1` set!"
           end
 
           if args.named.blank?
@@ -116,7 +116,7 @@ module Homebrew
           formulae = all_formulae = args.named.to_formulae
         elsif args.dependents?
           unless eval_all
-            raise UsageError, "`brew unbottled --dependents` needs `--eval-all` passed or `$HOMEBREW_EVAL_ALL` set!"
+            raise UsageError, "`brew unbottled --dependents` needs `--eval-all` passed or `HOMEBREW_EVAL_ALL=1` set!"
           end
 
           formulae = all_formulae = Formula.all(eval_all:)

Library/Homebrew/diagnostic.rb

@@ -475,7 +475,7 @@ module Homebrew
                           which resolves to: #{HOMEBREW_CELLAR.realpath}
 
           The recommended Homebrew installations are either:
-          (A) Have Cellar be a real directory inside of your HOMEBREW_PREFIX
+          (A) Have Cellar be a real directory inside of your `$HOMEBREW_PREFIX`
           (B) Symlink "bin/brew" into your prefix, but don't symlink "Cellar".
 
           Older installations of Homebrew may have created a symlinked Cellar, but this can

Library/Homebrew/download_strategy.rb

@@ -609,7 +609,7 @@ class CurlDownloadStrategy < AbstractFileDownloadStrategy
 
     if Homebrew::EnvConfig.no_insecure_redirect? &&
        url.start_with?("https://") && !resolved_url.start_with?("https://")
-      $stderr.puts "HTTPS to HTTP redirect detected and HOMEBREW_NO_INSECURE_REDIRECT is set."
+      $stderr.puts "HTTPS to HTTP redirect detected and `$HOMEBREW_NO_INSECURE_REDIRECT` is set."
       raise CurlDownloadStrategyError, url
     end
 

Library/Homebrew/exceptions.rb

@@ -331,9 +331,9 @@ end
 class TapCoreRemoteMismatchError < TapRemoteMismatchError
   def message
     <<~EOS
-      Tap #{name} remote does not match HOMEBREW_CORE_GIT_REMOTE.
+      Tap #{name} remote does not match `$HOMEBREW_CORE_GIT_REMOTE`.
       #{expected_remote} != #{actual_remote}
-      Please set HOMEBREW_CORE_GIT_REMOTE="#{actual_remote}" and run `brew update` instead.
+      Please set `HOMEBREW_CORE_GIT_REMOTE="#{actual_remote}"` and run `brew update` instead.
     EOS
   end
 end

Library/Homebrew/extend/kernel.rb

@@ -381,8 +381,8 @@ module Kernel
     unless silent
       opoo <<~EOS
         Using #{editor} because no editor was set in the environment.
-        This may change in the future, so we recommend setting EDITOR
+        This may change in the future, so we recommend setting `$EDITOR`
-        or HOMEBREW_EDITOR to your preferred text editor.
+        or `$HOMEBREW_EDITOR` to your preferred text editor.
       EOS
     end
 

Library/Homebrew/extend/os/linux/diagnostic.rb

@@ -37,7 +37,7 @@ module OS
 
           message + <<~EOS
             If you don't have administrative privileges on this machine,
-            create a directory and set the HOMEBREW_TEMP environment variable,
+            create a directory and set the `$HOMEBREW_TEMP` environment variable,
             for example:
               install -d -m 1755 ~/tmp
               #{Utils::Shell.set_variable_in_profile("HOMEBREW_TEMP", "~/tmp")}
@@ -53,7 +53,7 @@ module OS
 
           <<~EOS
             The directory #{HOMEBREW_TEMP} does not permit executing
-            programs. It is likely mounted as "noexec". Please set HOMEBREW_TEMP
+            programs. It is likely mounted as "noexec". Please set `$HOMEBREW_TEMP`
             in your #{Utils::Shell.profile} to a different directory, for example:
               export HOMEBREW_TEMP=~/tmp
               echo 'export HOMEBREW_TEMP=~/tmp' >> #{Utils::Shell.profile}
@@ -148,7 +148,7 @@ module OS
           return unless Homebrew::EnvConfig.bottle_domain.include?("linuxbrew")
 
           <<~EOS
-            Your HOMEBREW_BOTTLE_DOMAIN still contains "linuxbrew".
+            Your `$HOMEBREW_BOTTLE_DOMAIN` still contains "linuxbrew".
             You must unset it (or adjust it to not contain linuxbrew
             e.g. by using homebrew instead).
           EOS

Library/Homebrew/formula.rb

@@ -1973,7 +1973,7 @@ class Formula
   sig { params(source: Pathname, target: Pathname).returns(String) }
   def rpath(source: bin, target: lib)
     unless target.to_s.start_with?(HOMEBREW_PREFIX)
-      raise "rpath `target` should only be used for paths inside HOMEBREW_PREFIX!"
+      raise "rpath `target` should only be used for paths inside `$HOMEBREW_PREFIX`!"
     end
 
     "#{loader_path}/#{target.relative_path_from(source)}"
@@ -2244,7 +2244,7 @@ class Formula
   sig { params(eval_all: T::Boolean).returns(T::Array[Formula]) }
   def self.all(eval_all: false)
     if !eval_all && !Homebrew::EnvConfig.eval_all?
-      raise ArgumentError, "Formula#all without `--eval-all` or HOMEBREW_EVAL_ALL"
+      raise ArgumentError, "Formula#all cannot be used without `--eval-all` or `HOMEBREW_EVAL_ALL=1`"
     end
 
     (core_names + tap_files).filter_map do |name_or_file|

Library/Homebrew/formula_installer.rb

@@ -277,8 +277,8 @@ class FormulaInstaller
         prefix = Pathname(bottle.cellar.to_s).parent
         opoo <<~EOS
           Building #{formula.full_name} from source as the bottle needs:
-          - HOMEBREW_CELLAR: #{bottle.cellar} (yours is #{HOMEBREW_CELLAR})
+          - `HOMEBREW_CELLAR=#{bottle.cellar}` (yours is #{HOMEBREW_CELLAR})
-          - HOMEBREW_PREFIX: #{prefix} (yours is #{HOMEBREW_PREFIX})
+          - `HOMEBREW_PREFIX=#{prefix}` (yours is #{HOMEBREW_PREFIX})
         EOS
       end
       return false
@@ -1503,7 +1503,7 @@ on_request: installed_on_request?, options:)
 
           This typically indicates an invalid GitHub API token.
 
-          If you have `HOMEBREW_GITHUB_API_TOKEN` set, check it is correct
+          If you have `$HOMEBREW_GITHUB_API_TOKEN` set, check it is correct
           or unset it and instead run:
 
             gh auth login
@@ -1517,7 +1517,7 @@ on_request: installed_on_request?, options:)
           The bottle for #{formula.name} could not be verified.
 
           This typically indicates a missing GitHub API token, which you
-          can resolve either by setting `HOMEBREW_GITHUB_API_TOKEN` or
+          can resolve either by setting `$HOMEBREW_GITHUB_API_TOKEN` or
           by running:
 
             gh auth login
@@ -1649,7 +1649,7 @@ on_request: installed_on_request?, options:)
 
     if invalid_licenses.present?
       opoo <<~EOS
-        HOMEBREW_FORBIDDEN_LICENSES contains invalid license identifiers: #{invalid_licenses.to_sentence}
+        `$HOMEBREW_FORBIDDEN_LICENSES` contains invalid license identifiers: #{invalid_licenses.to_sentence}
         These licenses will not be forbidden. See the valid SPDX license identifiers at:
           #{Formatter.url("https://spdx.org/licenses/")}
         And the licenses for a formula with:
@@ -1671,7 +1671,7 @@ on_request: installed_on_request?, options:)
 
         raise CannotInstallFormulaError, <<~EOS
           The installation of #{formula.name} has a dependency on #{dep.name} where all
-          its licenses were forbidden by #{owner} in `HOMEBREW_FORBIDDEN_LICENSES`:
+          its licenses were forbidden by #{owner} in `$HOMEBREW_FORBIDDEN_LICENSES`:
             #{SPDX.license_expression_to_string dep_f.license}#{owner_contact}
         EOS
       end
@@ -1682,7 +1682,7 @@ on_request: installed_on_request?, options:)
     return unless SPDX.licenses_forbid_installation? formula.license, forbidden_licenses
 
     raise CannotInstallFormulaError, <<~EOS
-      #{formula.name}'s licenses are all forbidden by #{owner} in `HOMEBREW_FORBIDDEN_LICENSES`:
+      #{formula.name}'s licenses are all forbidden by #{owner} in `$HOMEBREW_FORBIDDEN_LICENSES`:
         #{SPDX.license_expression_to_string formula.license}#{owner_contact}
     EOS
   end
@@ -1703,9 +1703,9 @@ on_request: installed_on_request?, options:)
 
         error_message = "The installation of #{formula.name} has a dependency #{dep.name}\n" \
                         "from the #{dep_tap} tap but #{owner} "
-        error_message << "has not allowed this tap in `HOMEBREW_ALLOWED_TAPS`" unless dep_tap.allowed_by_env?
+        error_message << "has not allowed this tap in `$HOMEBREW_ALLOWED_TAPS`" unless dep_tap.allowed_by_env?
         error_message << " and\n" if !dep_tap.allowed_by_env? && dep_tap.forbidden_by_env?
-        error_message << "has forbidden this tap in `HOMEBREW_FORBIDDEN_TAPS`" if dep_tap.forbidden_by_env?
+        error_message << "has forbidden this tap in `$HOMEBREW_FORBIDDEN_TAPS`" if dep_tap.forbidden_by_env?
         error_message << ".#{owner_contact}"
 
         raise CannotInstallFormulaError, error_message
@@ -1719,9 +1719,9 @@ on_request: installed_on_request?, options:)
 
     error_message = "The installation of #{formula.full_name} has the tap #{formula_tap}\n" \
                     "but #{owner} "
-    error_message << "has not allowed this tap in `HOMEBREW_ALLOWED_TAPS`" unless formula_tap.allowed_by_env?
+    error_message << "has not allowed this tap in `$HOMEBREW_ALLOWED_TAPS`" unless formula_tap.allowed_by_env?
     error_message << " and\n" if !formula_tap.allowed_by_env? && formula_tap.forbidden_by_env?
-    error_message << "has forbidden this tap in `HOMEBREW_FORBIDDEN_TAPS`" if formula_tap.forbidden_by_env?
+    error_message << "has forbidden this tap in `$HOMEBREW_FORBIDDEN_TAPS`" if formula_tap.forbidden_by_env?
     error_message << ".#{owner_contact}"
 
     raise CannotInstallFormulaError, error_message
@@ -1751,7 +1751,7 @@ on_request: installed_on_request?, options:)
 
         raise CannotInstallFormulaError, <<~EOS
           The installation of #{formula.name} has a dependency #{dep_name}
-          but the #{dep_name} formula was forbidden by #{owner} in `HOMEBREW_FORBIDDEN_FORMULAE`.#{owner_contact}
+          but the #{dep_name} formula was forbidden by #{owner} in `$HOMEBREW_FORBIDDEN_FORMULAE`.#{owner_contact}
         EOS
       end
     end
@@ -1768,7 +1768,7 @@ on_request: installed_on_request?, options:)
 
     raise CannotInstallFormulaError, <<~EOS
       The installation of #{formula_name} was forbidden by #{owner}
-      in `HOMEBREW_FORBIDDEN_FORMULAE`.#{owner_contact}
+      in `$HOMEBREW_FORBIDDEN_FORMULAE`.#{owner_contact}
     EOS
   end
 

Library/Homebrew/formulary.rb

@@ -97,7 +97,7 @@ module Formulary
 
   using PathnameWriteMkpath
   def self.load_formula(name, path, contents, namespace, flags:, ignore_errors:)
-    raise "Formula loading disabled by HOMEBREW_DISABLE_LOAD_FORMULA!" if Homebrew::EnvConfig.disable_load_formula?
+    raise "Formula loading disabled by `$HOMEBREW_DISABLE_LOAD_FORMULA`!" if Homebrew::EnvConfig.disable_load_formula?
 
     require "formula"
     require "ignorable"

Library/Homebrew/rubocops/text.rb

@@ -38,7 +38,7 @@ module RuboCop
             end
 
             if find_node_method_by_name(body_node, :keg_only)&.source&.include?("HOMEBREW_PREFIX")
-              problem "`keg_only` reason should not include `HOMEBREW_PREFIX` " \
+              problem "`keg_only` reason should not include `$HOMEBREW_PREFIX` " \
                       "as it creates confusing `brew info` output."
             end
           end

Library/Homebrew/services/system.rb

@@ -90,8 +90,8 @@ module Homebrew
               opoo "uid and euid do not match, using user/* instead of gui/* domain!"
             end
             unless Homebrew::EnvConfig.no_env_hints?
-              puts "Hide this warning by setting HOMEBREW_SERVICES_NO_DOMAIN_WARNING."
+              puts "Hide this warning by setting `HOMEBREW_SERVICES_NO_DOMAIN_WARNING=1`."
-              puts "Hide these hints with HOMEBREW_NO_ENV_HINTS (see `man brew`)."
+              puts "Hide these hints with `HOMEBREW_NO_ENV_HINTS=1` (see `man brew`)."
             end
             @output_warning = T.let(true, T.nilable(TrueClass))
           end

Library/Homebrew/startup/bootsnap.rb

@@ -18,7 +18,7 @@ module Homebrew
 
     private_class_method def self.cache_dir
       cache = ENV.fetch("HOMEBREW_CACHE", nil) || ENV.fetch("HOMEBREW_DEFAULT_CACHE", nil)
-      raise "Needs HOMEBREW_CACHE or HOMEBREW_DEFAULT_CACHE!" if cache.nil? || cache.empty?
+      raise "Needs `$HOMEBREW_CACHE` or `$HOMEBREW_DEFAULT_CACHE`!" if cache.nil? || cache.empty?
 
       File.join(cache, "bootsnap", key)
     end

Library/Homebrew/system_command.rb

@@ -201,7 +201,9 @@ class SystemCommand
     askpass_flags = ENV.key?("SUDO_ASKPASS") ? ["-A"] : []
     user_flags = []
     if Homebrew::EnvConfig.sudo_through_sudo_user?
-      raise ArgumentError, "HOMEBREW_SUDO_THROUGH_SUDO_USER set but SUDO_USER unset!" if homebrew_sudo_user.blank?
+      if homebrew_sudo_user.blank?
+        raise ArgumentError, "`$HOMEBREW_SUDO_THROUGH_SUDO_USER` set but `$SUDO_USER` unset!"
+      end
 
       user_flags += ["--prompt", "Password for %p:", "-u", homebrew_sudo_user,
                      *askpass_flags,

Library/Homebrew/tap.rb

@@ -120,7 +120,7 @@ class Tap
       Set.new(allowed_tap_list.filter_map do |tap|
         Tap.fetch(tap)
       rescue Tap::InvalidNameError
-        opoo "Invalid tap name in `HOMEBREW_ALLOWED_TAPS`: #{tap}"
+        opoo "Invalid tap name in `$HOMEBREW_ALLOWED_TAPS`: #{tap}"
         nil
       end).freeze
     end
@@ -135,7 +135,7 @@ class Tap
       Set.new(forbidden_tap_list.filter_map do |tap|
         Tap.fetch(tap)
       rescue Tap::InvalidNameError
-        opoo "Invalid tap name in `HOMEBREW_FORBIDDEN_TAPS`: #{tap}"
+        opoo "Invalid tap name in `$HOMEBREW_FORBIDDEN_TAPS`: #{tap}"
         nil
       end).freeze
     end
@@ -432,9 +432,9 @@ class Tap
       end
 
       error_message = "The installation of the #{full_name} was requested but #{owner}\n"
-      error_message << "has not allowed this tap in `HOMEBREW_ALLOWED_TAPS`" unless allowed_by_env?
+      error_message << "has not allowed this tap in `$HOMEBREW_ALLOWED_TAPS`" unless allowed_by_env?
       error_message << " and\n" if !allowed_by_env? && forbidden_by_env?
-      error_message << "has forbidden this tap in `HOMEBREW_FORBIDDEN_TAPS`" if forbidden_by_env?
+      error_message << "has forbidden this tap in `$HOMEBREW_FORBIDDEN_TAPS`" if forbidden_by_env?
       error_message << ".#{owner_contact}"
 
       odie error_message

Library/Homebrew/test/cmd/desc_spec.rb

@@ -19,7 +19,7 @@ RSpec.describe Homebrew::Cmd::Desc do
     setup_test_formula "testball"
 
     expect { brew "desc", "--search", "testball" }
-      .to output(/`brew desc --search` needs `--eval-all` passed or `\$HOMEBREW_EVAL_ALL` set!/).to_stderr
+      .to output(/`brew desc --search` needs `--eval-all` passed or `HOMEBREW_EVAL_ALL=1` set!/).to_stderr
       .and be_a_failure
   end
 

Library/Homebrew/test/test_runner_formula_spec.rb

@@ -33,7 +33,7 @@ RSpec.describe TestRunnerFormula do
       expect(described_class.new(testball, eval_all: true).eval_all).to be(true)
     end
 
-    it "takes the value of `HOMEBREW_EVAL_ALL` at instantiation time if not specified" do
+    it "takes the value of HOMEBREW_EVAL_ALL at instantiation time if not specified" do
       allow(Homebrew::EnvConfig).to receive(:eval_all?).and_return(true)
       expect(described_class.new(testball).eval_all).to be(true)
 

Library/Homebrew/test/utils/curl_spec.rb

@@ -323,7 +323,7 @@ RSpec.describe "Utils::Curl" do
   end
 
   describe "::curl_executable" do
-    it "returns `HOMEBREW_BREWED_CURL_PATH` when `use_homebrew_curl` is `true`" do
+    it "returns HOMEBREW_BREWED_CURL_PATH when `use_homebrew_curl` is `true`" do
       expect(curl_executable(use_homebrew_curl: true)).to eq(HOMEBREW_BREWED_CURL_PATH)
     end
 

Library/Homebrew/upgrade.rb

@@ -170,7 +170,7 @@ module Homebrew
         if Homebrew::EnvConfig.no_installed_dependents_check?
           unless Homebrew::EnvConfig.no_env_hints?
             opoo <<~EOS
-              HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK is set: not checking for outdated
+              `$HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK` is set: not checking for outdated
               dependents or dependents with broken linkage!
             EOS
           end
@@ -418,8 +418,8 @@ module Homebrew
         return if Homebrew::EnvConfig.no_installed_dependents_check?
         return if @puts_no_installed_dependents_check_disable_message_if_not_already
 
-        puts "Disable this behaviour by setting HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK."
+        puts "Disable this behaviour by setting `HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK=1`."
-        puts "Hide these hints with HOMEBREW_NO_ENV_HINTS (see `man brew`)."
+        puts "Hide these hints with `HOMEBREW_NO_ENV_HINTS=1` (see `man brew`)."
         @puts_no_installed_dependents_check_disable_message_if_not_already = T.let(true, T.nilable(T::Boolean))
       end
 

Library/Homebrew/utils/github.rb

@@ -899,7 +899,7 @@ module GitHub
   end
 
   def self.count_repo_commits(nwo, user, from: nil, to: nil, max: nil)
-    odie "Cannot count commits, HOMEBREW_NO_GITHUB_API set!" if Homebrew::EnvConfig.no_github_api?
+    odie "Cannot count commits as `$HOMEBREW_NO_GITHUB_API` is set!" if Homebrew::EnvConfig.no_github_api?
 
     author_shas = repo_commits_for_user(nwo, user, "author", from, to, max)
     committer_shas = repo_commits_for_user(nwo, user, "committer", from, to, max)
@@ -922,7 +922,7 @@ module GitHub
     # BrewTestBot can open as many PRs as it wants.
     return false if ENV["HOMEBREW_TEST_BOT_AUTOBUMP"].present?
 
-    odie "Cannot count PRs, HOMEBREW_NO_GITHUB_API set!" if Homebrew::EnvConfig.no_github_api?
+    odie "Cannot count PRs as `$HOMEBREW_NO_GITHUB_API` is set!" if Homebrew::EnvConfig.no_github_api?
 
     query = <<~EOS
       query($after: String) {

Library/Homebrew/utils/github/api.rb

@@ -113,7 +113,7 @@ module GitHub
         when :env_token
           require "utils/formatter"
           <<~EOS
-            HOMEBREW_GITHUB_API_TOKEN may be invalid or expired; check:
+            `$HOMEBREW_GITHUB_API_TOKEN` may be invalid or expired; check:
               #{Formatter.url("https://github.com/settings/tokens")}
           EOS
         when :none

completions/fish/brew.fish

@@ -693,7 +693,7 @@ __fish_brew_complete_arg 'desc; and not __fish_seen_argument -l formula -l formu
 __fish_brew_complete_cmd 'determine-test-runners' 'Determines the runners used to test formulae or their dependents'
 __fish_brew_complete_arg 'determine-test-runners' -l all-supported -d 'Instead of selecting runners based on the chosen formula, return all supported runners'
 __fish_brew_complete_arg 'determine-test-runners' -l debug -d 'Display any debugging information'
-__fish_brew_complete_arg 'determine-test-runners' -l dependents -d 'Determine runners for testing dependents. Requires `--eval-all` or `$HOMEBREW_EVAL_ALL` to be set'
+__fish_brew_complete_arg 'determine-test-runners' -l dependents -d 'Determine runners for testing dependents. Requires `--eval-all` or `HOMEBREW_EVAL_ALL=1` to be set'
 __fish_brew_complete_arg 'determine-test-runners' -l eval-all -d 'Evaluate all available formulae, whether installed or not, to determine testing dependents. Enabled by default if `$HOMEBREW_EVAL_ALL` is set'
 __fish_brew_complete_arg 'determine-test-runners' -l help -d 'Show this message'
 __fish_brew_complete_arg 'determine-test-runners' -l quiet -d 'Make some output more quiet'

completions/zsh/_brew

@@ -875,7 +875,7 @@ _brew_determine_test_runners() {
   _arguments \
     '(--dependents)--all-supported[Instead of selecting runners based on the chosen formula, return all supported runners]' \
     '--debug[Display any debugging information]' \
-    '(--all-supported)--dependents[Determine runners for testing dependents. Requires `--eval-all` or `$HOMEBREW_EVAL_ALL` to be set]' \
+    '(--all-supported)--dependents[Determine runners for testing dependents. Requires `--eval-all` or `HOMEBREW_EVAL_ALL=1` to be set]' \
     '--eval-all[Evaluate all available formulae, whether installed or not, to determine testing dependents. Enabled by default if `$HOMEBREW_EVAL_ALL` is set]' \
     '--help[Show this message]' \
     '--quiet[Make some output more quiet]' \