diff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
index 399ede2172..14170c830c 100644
--- a/.github/PULL_REQUEST_TEMPLATE.md
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -1,7 +1,7 @@
-- [ ] Have you followed the guidelines in our [Contributing](https://github.com/Homebrew/brew/blob/master/CONTRIBUTING.md) document?
+- [ ] Have you followed the guidelines in our [Contributing](https://github.com/Homebrew/brew/blob/HEAD/CONTRIBUTING.md) document?
 - [ ] Have you checked to ensure there aren't other open [Pull Requests](https://github.com/Homebrew/brew/pulls) for the same change?
 - [ ] Have you added an explanation of what your changes do and why you'd like us to include them?
-- [ ] Have you written new tests for your changes? [Here's an example](https://github.com/Homebrew/brew/blob/master/Library/Homebrew/test/PATH_spec.rb).
+- [ ] Have you written new tests for your changes? [Here's an example](https://github.com/Homebrew/brew/blob/HEAD/Library/Homebrew/test/PATH_spec.rb).
 - [ ] Have you successfully run `brew style` with your changes locally?
 - [ ] Have you successfully run `brew tests` with your changes locally?
 
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a1618b90cd..dfd91c66cd 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,6 +1,6 @@
 # Contributing to Homebrew
 
-First time contributing to Homebrew? Read our [Code of Conduct](https://github.com/Homebrew/.github/blob/master/CODE_OF_CONDUCT.md#code-of-conduct) and review [How To Open a Homebrew Pull Request](https://docs.brew.sh/How-To-Open-a-Homebrew-Pull-Request).
+First time contributing to Homebrew? Read our [Code of Conduct](https://github.com/Homebrew/.github/blob/HEAD/CODE_OF_CONDUCT.md#code-of-conduct) and review [How To Open a Homebrew Pull Request](https://docs.brew.sh/How-To-Open-a-Homebrew-Pull-Request).
 
 ### Report a bug
 
diff --git a/Library/.rubocop_cask.yml b/Library/.rubocop_cask.yml
index 2c128a436a..db3d6caf66 100644
--- a/Library/.rubocop_cask.yml
+++ b/Library/.rubocop_cask.yml
@@ -1,7 +1,7 @@
 inherit_from: ./.rubocop_shared.yml
 
 Cask/HomepageMatchesUrl:
-  Description: 'Ensure that the homepage and url match, otherwise add a comment. More info at https://github.com/Homebrew/homebrew-cask/blob/master/doc/cask_language_reference/stanzas/url.md#when-url-and-homepage-hostnames-differ-add-a-comment'
+  Description: 'Ensure that the homepage and url match, otherwise add a comment. More info at https://github.com/Homebrew/homebrew-cask/blob/HEAD/doc/cask_language_reference/stanzas/url.md#when-url-and-homepage-hostnames-differ-add-a-comment'
   Enabled: true
   Exclude:
   - '**/test/support/fixtures/cask/Casks/**/*.rb'
@@ -15,11 +15,11 @@ Cask/NoDslVersion:
   Enabled: true
 
 Cask/StanzaGrouping:
-  Description: 'Ensure that cask stanzas are grouped correctly. More info at https://github.com/Homebrew/homebrew-cask/blob/master/CONTRIBUTING.md#stanza-order'
+  Description: 'Ensure that cask stanzas are grouped correctly. More info at https://github.com/Homebrew/homebrew-cask/blob/HEAD/CONTRIBUTING.md#stanza-order'
   Enabled: true
 
 Cask/StanzaOrder:
-  Description: 'Ensure that cask stanzas are sorted correctly. More info at https://github.com/Homebrew/homebrew-cask/blob/master/CONTRIBUTING.md#stanza-order'
+  Description: 'Ensure that cask stanzas are sorted correctly. More info at https://github.com/Homebrew/homebrew-cask/blob/HEAD/CONTRIBUTING.md#stanza-order'
   Enabled: true
 
 Layout/HashAlignment:
diff --git a/Library/Homebrew/cask/audit.rb b/Library/Homebrew/cask/audit.rb
index 3a8478e5f0..db019bda75 100644
--- a/Library/Homebrew/cask/audit.rb
+++ b/Library/Homebrew/cask/audit.rb
@@ -219,7 +219,7 @@ module Cask
     def check_hosting_with_appcast
       return if cask.appcast
 
-      add_appcast = "please add an appcast. See https://github.com/Homebrew/homebrew-cask/blob/master/doc/cask_language_reference/stanzas/appcast.md"
+      add_appcast = "please add an appcast. See https://github.com/Homebrew/homebrew-cask/blob/HEAD/doc/cask_language_reference/stanzas/appcast.md"
 
       case cask.url.to_s
       when %r{github.com/([^/]+)/([^/]+)/releases/download/(\S+)}
@@ -246,9 +246,9 @@ module Cask
     def check_download_url_format
       odebug "Auditing URL format"
       if bad_sourceforge_url?
-        add_warning "SourceForge URL format incorrect. See https://github.com/Homebrew/homebrew-cask/blob/master/doc/cask_language_reference/stanzas/url.md#sourceforgeosdn-urls"
+        add_warning "SourceForge URL format incorrect. See https://github.com/Homebrew/homebrew-cask/blob/HEAD/doc/cask_language_reference/stanzas/url.md#sourceforgeosdn-urls"
       elsif bad_osdn_url?
-        add_warning "OSDN URL format incorrect. See https://github.com/Homebrew/homebrew-cask/blob/master/doc/cask_language_reference/stanzas/url.md#sourceforgeosdn-urls"
+        add_warning "OSDN URL format incorrect. See https://github.com/Homebrew/homebrew-cask/blob/HEAD/doc/cask_language_reference/stanzas/url.md#sourceforgeosdn-urls"
       end
     end
 
@@ -355,7 +355,7 @@ module Cask
     end
 
     def core_formula_url
-      "#{core_tap.default_remote}/blob/master/Formula/#{cask.token}.rb"
+      "#{core_tap.default_remote}/blob/HEAD/Formula/#{cask.token}.rb"
     end
 
     def check_download
diff --git a/Library/Homebrew/cask/cmd/info.rb b/Library/Homebrew/cask/cmd/info.rb
index e4acbbe56d..5669d0dcd3 100644
--- a/Library/Homebrew/cask/cmd/info.rb
+++ b/Library/Homebrew/cask/cmd/info.rb
@@ -97,7 +97,7 @@ module Cask
         url = if cask.tap.custom_remote? && !cask.tap.remote.nil?
           cask.tap.remote
         else
-          "#{cask.tap.default_remote}/blob/master/Casks/#{cask.token}.rb"
+          "#{cask.tap.default_remote}/blob/HEAD/Casks/#{cask.token}.rb"
         end
 
         "From: #{Formatter.url(url)}"
diff --git a/Library/Homebrew/cask/exceptions.rb b/Library/Homebrew/cask/exceptions.rb
index 7a337034c9..7679aa043a 100644
--- a/Library/Homebrew/cask/exceptions.rb
+++ b/Library/Homebrew/cask/exceptions.rb
@@ -151,7 +151,7 @@ module Cask
             File: #{path}
         To retry an incomplete download, remove the file above.
         If the issue persists, visit:
-          #{Formatter.url("https://github.com/Homebrew/homebrew-cask/blob/master/doc/reporting_bugs/checksum_does_not_match_error.md")}
+          #{Formatter.url("https://github.com/Homebrew/homebrew-cask/blob/HEAD/doc/reporting_bugs/checksum_does_not_match_error.md")}
       EOS
     end
   end
diff --git a/Library/Homebrew/cmd/--cache.rb b/Library/Homebrew/cmd/--cache.rb
index de6c1ac0a0..1dd0bb2c5e 100644
--- a/Library/Homebrew/cmd/--cache.rb
+++ b/Library/Homebrew/cmd/--cache.rb
@@ -22,9 +22,9 @@ module Homebrew
       switch "--force-bottle",
              description: "Show the cache file used when pouring a bottle."
       switch "--formula",
-             description: "Show cache files for only formulae"
+             description: "Only show cache files for formulae."
       switch "--cask",
-             description: "Show cache files for only casks"
+             description: "Only show cache files for casks."
       conflicts "--build-from-source", "--force-bottle"
       conflicts "--formula", "--cask"
     end
diff --git a/Library/Homebrew/cmd/info.rb b/Library/Homebrew/cmd/info.rb
index 312e50c51e..51a29e1b57 100644
--- a/Library/Homebrew/cmd/info.rb
+++ b/Library/Homebrew/cmd/info.rb
@@ -140,7 +140,7 @@ module Homebrew
 
   def github_remote_path(remote, path)
     if remote =~ %r{^(?:https?://|git(?:@|://))github\.com[:/](.+)/(.+?)(?:\.git)?$}
-      "https://github.com/#{Regexp.last_match(1)}/#{Regexp.last_match(2)}/blob/master/#{path}"
+      "https://github.com/#{Regexp.last_match(1)}/#{Regexp.last_match(2)}/blob/HEAD/#{path}"
     else
       "#{remote}/#{path}"
     end
diff --git a/Library/Homebrew/dev-cmd/create.rb b/Library/Homebrew/dev-cmd/create.rb
index 3fe90865c6..7449ace42c 100644
--- a/Library/Homebrew/dev-cmd/create.rb
+++ b/Library/Homebrew/dev-cmd/create.rb
@@ -23,6 +23,8 @@ module Homebrew
              description: "Create a basic template for an Autotools-style build."
       switch "--cmake",
              description: "Create a basic template for a CMake-style build."
+      switch "--crystal",
+             description: "Create a basic template for a Crystal build."
       switch "--go",
              description: "Create a basic template for a Go build."
       switch "--meson",
@@ -50,7 +52,7 @@ module Homebrew
       switch :force
       switch :verbose
       switch :debug
-      conflicts "--autotools", "--cmake", "--go", "--meson", "--perl", "--python", "--rust"
+      conflicts "--autotools", "--cmake", "--crystal", "--go", "--meson", "--perl", "--python", "--rust"
       named 1
     end
   end
@@ -82,6 +84,8 @@ module Homebrew
       :autotools
     elsif args.meson?
       :meson
+    elsif args.crystal?
+      :crystal
     elsif args.go?
       :go
     elsif args.perl?
diff --git a/Library/Homebrew/dev-cmd/mirror.rb b/Library/Homebrew/dev-cmd/mirror.rb
index e124175205..25c6317363 100644
--- a/Library/Homebrew/dev-cmd/mirror.rb
+++ b/Library/Homebrew/dev-cmd/mirror.rb
@@ -13,10 +13,10 @@ module Homebrew
 
         Reupload the stable URL of a formula to Bintray for use as a mirror.
       EOS
-      flag "--bintray-org=",
-           description: "Upload to the specified Bintray organisation (default: homebrew)."
-      flag "--bintray-repo=",
-           description: "Upload to the specified Bintray repository (default: mirror)."
+      flag   "--bintray-org=",
+             description: "Upload to the specified Bintray organisation (default: `homebrew`)."
+      flag   "--bintray-repo=",
+             description: "Upload to the specified Bintray repository (default: `mirror`)."
       switch "--no-publish",
              description: "Upload to Bintray, but don't publish."
       switch :verbose
diff --git a/Library/Homebrew/dev-cmd/pr-pull.rb b/Library/Homebrew/dev-cmd/pr-pull.rb
index bbd1b097e4..c5f82ec116 100644
--- a/Library/Homebrew/dev-cmd/pr-pull.rb
+++ b/Library/Homebrew/dev-cmd/pr-pull.rb
@@ -34,18 +34,18 @@ module Homebrew
              description: "When a patch fails to apply, leave in progress and allow user to resolve, "\
                           "instead of aborting."
       flag   "--workflow=",
-             description: "Retrieve artifacts from the specified workflow (default: tests.yml)."
+             description: "Retrieve artifacts from the specified workflow (default: `tests.yml`)."
       flag   "--artifact=",
-             description: "Download artifacts with the specified name (default: bottles)."
+             description: "Download artifacts with the specified name (default: `bottles`)."
       flag   "--bintray-org=",
-             description: "Upload to the specified Bintray organisation (default: homebrew)."
+             description: "Upload to the specified Bintray organisation (default: `homebrew`)."
       flag   "--tap=",
-             description: "Target tap repository (default: homebrew/core)."
+             description: "Target tap repository (default: `homebrew/core`)."
       flag   "--root-url=",
              description: "Use the specified <URL> as the root of the bottle's URL instead of Homebrew's default."
       flag   "--bintray-mirror=",
              description: "Use the specified Bintray repository to automatically mirror stable URLs "\
-                          "defined in the formulae (default: mirror)"
+                          "defined in the formulae (default: `mirror`)."
       switch :verbose
       switch :debug
       min_named 1
diff --git a/Library/Homebrew/dev-cmd/pr-upload.rb b/Library/Homebrew/dev-cmd/pr-upload.rb
index 86b1d83717..f591bf77dd 100644
--- a/Library/Homebrew/dev-cmd/pr-upload.rb
+++ b/Library/Homebrew/dev-cmd/pr-upload.rb
@@ -15,12 +15,12 @@ module Homebrew
       EOS
       switch "--no-publish",
              description: "Apply the bottle commit and upload the bottles, but don't publish them."
-      switch "--dry-run", "-n",
+      switch "-n", "--dry-run",
              description: "Print what would be done rather than doing it."
-      flag "--bintray-org=",
-           description: "Upload to the specified Bintray organisation (default: homebrew)."
-      flag "--root-url=",
-           description: "Use the specified <URL> as the root of the bottle's URL instead of Homebrew's default."
+      flag   "--bintray-org=",
+             description: "Upload to the specified Bintray organisation (default: `homebrew`)."
+      flag   "--root-url=",
+             description: "Use the specified <URL> as the root of the bottle's URL instead of Homebrew's default."
       switch :verbose
       switch :debug
     end
diff --git a/Library/Homebrew/extend/os/linux/hardware/cpu.rb b/Library/Homebrew/extend/os/linux/hardware/cpu.rb
index 4f37ac614b..b1fb08e2d2 100644
--- a/Library/Homebrew/extend/os/linux/hardware/cpu.rb
+++ b/Library/Homebrew/extend/os/linux/hardware/cpu.rb
@@ -21,7 +21,7 @@ module Hardware
         return :dunno unless intel?
 
         # See https://software.intel.com/en-us/articles/intel-architecture-and-processor-identification-with-cpuid-model-and-family-numbers
-        # and https://github.com/llvm-mirror/llvm/blob/master/lib/Support/Host.cpp
+        # and https://github.com/llvm-mirror/llvm/blob/HEAD/lib/Support/Host.cpp
         # and https://en.wikipedia.org/wiki/List_of_Intel_CPU_microarchitectures#Roadmap
         cpu_family = cpuinfo[/^cpu family\s*: ([0-9]+)/, 1].to_i
         cpu_model = cpuinfo[/^model\s*: ([0-9]+)/, 1].to_i
diff --git a/Library/Homebrew/extend/os/mac/utils/bottles.rb b/Library/Homebrew/extend/os/mac/utils/bottles.rb
index 08e4fb2611..99a22c3513 100644
--- a/Library/Homebrew/extend/os/mac/utils/bottles.rb
+++ b/Library/Homebrew/extend/os/mac/utils/bottles.rb
@@ -6,7 +6,9 @@ module Utils
       undef tag
 
       def tag
-        MacOS.version.to_sym
+        tag = MacOS.version.to_sym
+        tag = "#{tag}_arm".to_sym if Hardware::CPU.arm?
+        tag
       end
     end
 
diff --git a/Library/Homebrew/formula_creator.rb b/Library/Homebrew/formula_creator.rb
index 5e734c9072..6a76ee6849 100644
--- a/Library/Homebrew/formula_creator.rb
+++ b/Library/Homebrew/formula_creator.rb
@@ -103,6 +103,8 @@ module Homebrew
 
         <% if mode == :cmake %>
           depends_on "cmake" => :build
+        <% elsif mode == :crystal %>
+          depends_on "crystal" => :build
         <% elsif mode == :go %>
           depends_on "go" => :build
         <% elsif mode == :meson %>
@@ -138,6 +140,9 @@ module Homebrew
                                   "--disable-dependency-tracking",
                                   "--disable-silent-rules",
                                   "--prefix=\#{prefix}"
+        <% elsif mode == :crystal %>
+            system "shards", "build", "--release"
+            bin.install "bin/#{name}"
         <% elsif mode == :go %>
             system "go", "build", *std_go_args
         <% elsif mode == :meson %>
diff --git a/Library/Homebrew/help.rb b/Library/Homebrew/help.rb
index 0e41977c72..57196edf7c 100644
--- a/Library/Homebrew/help.rb
+++ b/Library/Homebrew/help.rb
@@ -103,7 +103,7 @@ module Homebrew
       help_lines = command_help_lines(path)
       return if help_lines.blank?
 
-      Formatter.wrap(help_lines.join.delete_prefix("  "), COMMAND_DESC_WIDTH)
+      Formatter.wrap(help_lines.join, COMMAND_DESC_WIDTH)
                .sub("@hide_from_man_page ", "")
                .sub(/^\* /, "#{Tty.bold}Usage: brew#{Tty.reset} ")
                .gsub(/`(.*?)`/m, "#{Tty.bold}\\1#{Tty.reset}")
diff --git a/Library/Homebrew/keg.rb b/Library/Homebrew/keg.rb
index 16818f0ce2..7edb23361b 100644
--- a/Library/Homebrew/keg.rb
+++ b/Library/Homebrew/keg.rb
@@ -80,7 +80,7 @@ class Keg
   ).map { |dir| HOMEBREW_PREFIX/dir }.sort.uniq.freeze
 
   # Keep relatively in sync with
-  # https://github.com/Homebrew/install/blob/master/install
+  # https://github.com/Homebrew/install/blob/HEAD/install
   MUST_EXIST_DIRECTORIES = (MUST_EXIST_SUBDIRECTORIES + [
     HOMEBREW_CELLAR,
   ].sort.uniq).freeze
diff --git a/Library/Homebrew/linkage_checker.rb b/Library/Homebrew/linkage_checker.rb
index 55b14339de..915352842d 100644
--- a/Library/Homebrew/linkage_checker.rb
+++ b/Library/Homebrew/linkage_checker.rb
@@ -3,6 +3,7 @@
 require "keg"
 require "formula"
 require "linkage_cache_store"
+require "fiddle"
 
 class LinkageChecker
   attr_reader :undeclared_deps
@@ -125,6 +126,11 @@ class LinkageChecker
 
           if (dep = dylib_to_dep(dylib))
             @broken_deps[dep] |= [dylib]
+          elsif MacOS.version >= :big_sur && dylib_found_via_dlopen(dylib)
+            # If we cannot associate the dylib with a dependency, then it may be a system library.
+            # In macOS Big Sur and later, system libraries do not exist on-disk and instead exist in a cache.
+            # If dlopen finds the dylib, then the linkage is not broken.
+            @system_dylibs << dylib
           else
             @broken_dylibs << dylib
           end
@@ -151,6 +157,13 @@ class LinkageChecker
   end
   alias generic_check_dylibs check_dylibs
 
+  def dylib_found_via_dlopen(dylib)
+    Fiddle.dlopen(dylib).close
+    true
+  rescue Fiddle::DLError
+    false
+  end
+
   def check_formula_deps
     filter_out = proc do |dep|
       next true if dep.build?
diff --git a/Library/Homebrew/os/mac.rb b/Library/Homebrew/os/mac.rb
index f559bfacf9..27749cf0c8 100644
--- a/Library/Homebrew/os/mac.rb
+++ b/Library/Homebrew/os/mac.rb
@@ -43,14 +43,14 @@ module OS
     def latest_stable_version
       # TODO: bump version when new macOS is released and also update
       # references in docs/Installation.md and
-      # https://github.com/Homebrew/install/blob/master/install
+      # https://github.com/Homebrew/install/blob/HEAD/install
       Version.new "10.15"
     end
 
     def outdated_release?
       # TODO: bump version when new macOS is released and also update
       # references in docs/Installation.md and
-      # https://github.com/Homebrew/install/blob/master/install
+      # https://github.com/Homebrew/install/blob/HEAD/install
       version < "10.13"
     end
 
diff --git a/Library/Homebrew/rubocops/cask/homepage_matches_url.rb b/Library/Homebrew/rubocops/cask/homepage_matches_url.rb
index d142ad7170..ca2bea9d6d 100644
--- a/Library/Homebrew/rubocops/cask/homepage_matches_url.rb
+++ b/Library/Homebrew/rubocops/cask/homepage_matches_url.rb
@@ -14,7 +14,7 @@ module RuboCop
         include CaskHelp
 
         REFERENCE_URL =
-          "https://github.com/Homebrew/homebrew-cask/blob/master/doc/" \
+          "https://github.com/Homebrew/homebrew-cask/blob/HEAD/doc/" \
           "cask_language_reference/stanzas/url.md#when-url-and-homepage-hostnames-differ-add-a-comment"
 
         COMMENT_FORMAT = /# [^ ]+ was verified as official when first introduced to the cask/.freeze
diff --git a/Library/Homebrew/rubocops/cask/stanza_grouping.rb b/Library/Homebrew/rubocops/cask/stanza_grouping.rb
index aec43875c7..c29d8d71c8 100644
--- a/Library/Homebrew/rubocops/cask/stanza_grouping.rb
+++ b/Library/Homebrew/rubocops/cask/stanza_grouping.rb
@@ -6,7 +6,7 @@ module RuboCop
   module Cop
     module Cask
       # This cop checks that a cask's stanzas are grouped correctly.
-      # See https://github.com/Homebrew/homebrew-cask/blob/master/CONTRIBUTING.md#stanza-order
+      # See https://github.com/Homebrew/homebrew-cask/blob/HEAD/CONTRIBUTING.md#stanza-order
       # for more info.
       class StanzaGrouping < Cop
         extend Forwardable
diff --git a/Library/Homebrew/rubocops/cask/stanza_order.rb b/Library/Homebrew/rubocops/cask/stanza_order.rb
index 2a81bdb113..71dad3cb8e 100644
--- a/Library/Homebrew/rubocops/cask/stanza_order.rb
+++ b/Library/Homebrew/rubocops/cask/stanza_order.rb
@@ -6,7 +6,7 @@ module RuboCop
   module Cop
     module Cask
       # This cop checks that a cask's stanzas are ordered correctly.
-      # See https://github.com/Homebrew/homebrew-cask/blob/master/CONTRIBUTING.md#stanza-order
+      # See https://github.com/Homebrew/homebrew-cask/blob/HEAD/CONTRIBUTING.md#stanza-order
       # for more info.
       class StanzaOrder < Cop
         extend Forwardable
diff --git a/Library/Homebrew/rubocops/extend/formula.rb b/Library/Homebrew/rubocops/extend/formula.rb
index 81281cd63a..34b8a4a7f1 100644
--- a/Library/Homebrew/rubocops/extend/formula.rb
+++ b/Library/Homebrew/rubocops/extend/formula.rb
@@ -495,7 +495,15 @@ module RuboCop
         when :str
           node.str_content
         when :dstr
-          node.each_child_node(:str).map(&:str_content).join
+          content = ""
+          node.each_child_node(:str, :begin) do |child|
+            content += if child.begin_type?
+              child.source
+            else
+              child.str_content
+            end
+          end
+          content
         when :const
           node.const_name
         when :sym
diff --git a/Library/Homebrew/sorbet/rbi/gems/activesupport@6.0.3.1.rbi b/Library/Homebrew/sorbet/rbi/gems/activesupport@6.0.3.2.rbi
similarity index 74%
rename from Library/Homebrew/sorbet/rbi/gems/activesupport@6.0.3.1.rbi
rename to Library/Homebrew/sorbet/rbi/gems/activesupport@6.0.3.2.rbi
index 5e3ec3f757..47ac6bc2cf 100644
--- a/Library/Homebrew/sorbet/rbi/gems/activesupport@6.0.3.1.rbi
+++ b/Library/Homebrew/sorbet/rbi/gems/activesupport@6.0.3.2.rbi
@@ -1,5 +1,5 @@
 # This file is autogenerated. Do not edit it by hand. Regenerate it with:
-#   tapioca sync
+#   tapioca sync --exclude json
 
 # typed: false
 
diff --git a/Library/Homebrew/sorbet/rbi/gems/diff-lcs@1.3.rbi b/Library/Homebrew/sorbet/rbi/gems/diff-lcs@1.4.2.rbi
similarity index 73%
rename from Library/Homebrew/sorbet/rbi/gems/diff-lcs@1.3.rbi
rename to Library/Homebrew/sorbet/rbi/gems/diff-lcs@1.4.2.rbi
index 27b1fb4bc6..198c6b42fc 100644
--- a/Library/Homebrew/sorbet/rbi/gems/diff-lcs@1.3.rbi
+++ b/Library/Homebrew/sorbet/rbi/gems/diff-lcs@1.4.2.rbi
@@ -1,5 +1,5 @@
 # This file is autogenerated. Do not edit it by hand. Regenerate it with:
-#   tapioca sync
+#   tapioca sync --exclude json
 
 # typed: true
 
diff --git a/Library/Homebrew/sorbet/rbi/gems/parallel@1.19.1.rbi b/Library/Homebrew/sorbet/rbi/gems/parallel@1.19.2.rbi
similarity index 98%
rename from Library/Homebrew/sorbet/rbi/gems/parallel@1.19.1.rbi
rename to Library/Homebrew/sorbet/rbi/gems/parallel@1.19.2.rbi
index c8028fd195..29e0e10469 100644
--- a/Library/Homebrew/sorbet/rbi/gems/parallel@1.19.1.rbi
+++ b/Library/Homebrew/sorbet/rbi/gems/parallel@1.19.2.rbi
@@ -1,5 +1,5 @@
 # This file is autogenerated. Do not edit it by hand. Regenerate it with:
-#   tapioca sync
+#   tapioca sync --exclude json
 
 # typed: true
 
diff --git a/Library/Homebrew/sorbet/rbi/gems/parser@2.7.1.3.rbi b/Library/Homebrew/sorbet/rbi/gems/parser@2.7.1.4.rbi
similarity index 98%
rename from Library/Homebrew/sorbet/rbi/gems/parser@2.7.1.3.rbi
rename to Library/Homebrew/sorbet/rbi/gems/parser@2.7.1.4.rbi
index 282993d64d..67b7fecda2 100644
--- a/Library/Homebrew/sorbet/rbi/gems/parser@2.7.1.3.rbi
+++ b/Library/Homebrew/sorbet/rbi/gems/parser@2.7.1.4.rbi
@@ -1,5 +1,5 @@
 # This file is autogenerated. Do not edit it by hand. Regenerate it with:
-#   tapioca sync
+#   tapioca sync --exclude json
 
 # typed: true
 
@@ -53,7 +53,9 @@ class Parser::AST::Processor < ::AST::Processor
   def on_empty_else(node); end
   def on_ensure(node); end
   def on_erange(node); end
+  def on_find_pattern(node); end
   def on_for(node); end
+  def on_forward_arg(node); end
   def on_gvar(node); end
   def on_gvasgn(node); end
   def on_hash(node); end
@@ -217,9 +219,11 @@ class Parser::Builders::Default
   def emit_file_line_as_literals; end
   def emit_file_line_as_literals=(_); end
   def false(false_t); end
+  def find_pattern(lbrack_t, elements, rbrack_t); end
   def float(float_t); end
   def for(for_t, iterator, in_t, iteratee, do_t, body, end_t); end
-  def forward_args(begin_t, dots_t, end_t); end
+  def forward_arg(dots_t); end
+  def forward_only_args(begin_t, dots_t, end_t); end
   def forwarded_args(dots_t); end
   def gvar(token); end
   def hash_pattern(lbrace_t, kwargs, rbrace_t); end
@@ -366,6 +370,8 @@ class Parser::Builders::Default
   def self.emit_arg_inside_procarg0=(_); end
   def self.emit_encoding; end
   def self.emit_encoding=(_); end
+  def self.emit_forward_arg; end
+  def self.emit_forward_arg=(_); end
   def self.emit_index; end
   def self.emit_index=(_); end
   def self.emit_lambda; end
@@ -1024,8 +1030,11 @@ class Parser::Source::TreeRewriter
 
   def initialize(source_buffer, crossing_deletions: _, different_replacements: _, swallowed_insertions: _); end
 
+  def as_nested_actions; end
+  def as_replacements; end
   def diagnostics; end
   def empty?; end
+  def import!(foreign_rewriter, offset: _); end
   def in_transaction?; end
   def insert_after(range, content); end
   def insert_after_multi(range, text); end
@@ -1059,10 +1068,13 @@ class Parser::Source::TreeRewriter::Action
   def initialize(range, enforcer, insert_before: _, replacement: _, insert_after: _, children: _); end
 
   def combine(action); end
+  def contract; end
   def empty?; end
   def insert_after; end
   def insert_before; end
   def insertion?; end
+  def moved(source_buffer, offset); end
+  def nested_actions; end
   def ordered_replacements; end
   def range; end
   def replacement; end
diff --git a/Library/Homebrew/sorbet/rbi/gems/rubocop@0.85.1.rbi b/Library/Homebrew/sorbet/rbi/gems/rubocop@0.86.0.rbi
similarity index 99%
rename from Library/Homebrew/sorbet/rbi/gems/rubocop@0.85.1.rbi
rename to Library/Homebrew/sorbet/rbi/gems/rubocop@0.86.0.rbi
index b9895aecaf..48ac41d0c8 100644
--- a/Library/Homebrew/sorbet/rbi/gems/rubocop@0.85.1.rbi
+++ b/Library/Homebrew/sorbet/rbi/gems/rubocop@0.86.0.rbi
@@ -1,5 +1,5 @@
 # This file is autogenerated. Do not edit it by hand. Regenerate it with:
-#   tapioca sync
+#   tapioca sync --exclude json
 
 # typed: true
 
@@ -3415,6 +3415,19 @@ end
 
 RuboCop::Cop::Lint::CircularArgumentReference::MSG = T.let(T.unsafe(nil), String)
 
+class RuboCop::Cop::Lint::ConstantResolution < ::RuboCop::Cop::Cop
+  def on_const(node); end
+  def unqualified_const?(node = _); end
+
+  private
+
+  def allowed_names; end
+  def const_name?(name); end
+  def ignored_names; end
+end
+
+RuboCop::Cop::Lint::ConstantResolution::MSG = T.let(T.unsafe(nil), String)
+
 class RuboCop::Cop::Lint::Debugger < ::RuboCop::Cop::Cop
   def binding_irb_call?(node = _); end
   def debugger_call?(node = _); end
@@ -4004,6 +4017,7 @@ end
 RuboCop::Cop::Lint::PercentSymbolArray::MSG = T.let(T.unsafe(nil), String)
 
 class RuboCop::Cop::Lint::RaiseException < ::RuboCop::Cop::Cop
+  def autocorrect(node); end
   def exception?(node = _); end
   def exception_new_with_message?(node = _); end
   def on_send(node); end
@@ -4170,6 +4184,7 @@ RuboCop::Cop::Lint::RedundantWithObject::MSG_EACH_WITH_OBJECT = T.let(T.unsafe(n
 RuboCop::Cop::Lint::RedundantWithObject::MSG_WITH_OBJECT = T.let(T.unsafe(nil), String)
 
 class RuboCop::Cop::Lint::RegexpAsCondition < ::RuboCop::Cop::Cop
+  def autocorrect(node); end
   def on_match_current_line(node); end
 end
 
@@ -4762,11 +4777,14 @@ class RuboCop::Cop::Metrics::CyclomaticComplexity < ::RuboCop::Cop::Cop
   include(::RuboCop::Cop::ConfigurableMax)
   include(::RuboCop::Cop::IgnoredMethods)
   include(::RuboCop::Cop::MethodComplexity)
+  include(::RuboCop::Cop::Metrics::Utils::IteratingBlock)
 
 
   private
 
-  def complexity_score_for(_node); end
+  def block_method(node); end
+  def complexity_score_for(node); end
+  def count_block?(block); end
 end
 
 RuboCop::Cop::Metrics::CyclomaticComplexity::COUNTED_NODES = T.let(T.unsafe(nil), Array)
@@ -4857,6 +4875,14 @@ RuboCop::Cop::Metrics::Utils::AbcSizeCalculator::BRANCH_NODES = T.let(T.unsafe(n
 
 RuboCop::Cop::Metrics::Utils::AbcSizeCalculator::CONDITION_NODES = T.let(T.unsafe(nil), Array)
 
+module RuboCop::Cop::Metrics::Utils::IteratingBlock
+  def block_method_name(node); end
+  def iterating_block?(node); end
+  def iterating_method?(name); end
+end
+
+RuboCop::Cop::Metrics::Utils::IteratingBlock::KNOWN_ITERATING_METHODS = T.let(T.unsafe(nil), Set)
+
 module RuboCop::Cop::Migration
 end
 
@@ -5478,6 +5504,9 @@ module RuboCop::Cop::RegexpLiteralHelp
   private
 
   def freespace_mode_regexp?(node); end
+  def pattern_source(node); end
+  def replace_match_with_spaces(source, pattern); end
+  def source_with_comments_and_interpolations_blanked(child, freespace_mode); end
 end
 
 class RuboCop::Cop::Registry
@@ -7376,6 +7405,7 @@ end
 RuboCop::Cop::Style::MultilineMethodSignature::MSG = T.let(T.unsafe(nil), String)
 
 class RuboCop::Cop::Style::MultilineTernaryOperator < ::RuboCop::Cop::Cop
+  def autocorrect(node); end
   def on_if(node); end
 end
 
@@ -7509,7 +7539,13 @@ end
 RuboCop::Cop::Style::NestedParenthesizedCalls::MSG = T.let(T.unsafe(nil), String)
 
 class RuboCop::Cop::Style::NestedTernaryOperator < ::RuboCop::Cop::Cop
+  def autocorrect(node); end
   def on_if(node); end
+
+  private
+
+  def if_node(node); end
+  def remove_parentheses(source); end
 end
 
 RuboCop::Cop::Style::NestedTernaryOperator::MSG = T.let(T.unsafe(nil), String)
@@ -8056,6 +8092,26 @@ RuboCop::Cop::Style::RedundantException::MSG_1 = T.let(T.unsafe(nil), String)
 
 RuboCop::Cop::Style::RedundantException::MSG_2 = T.let(T.unsafe(nil), String)
 
+class RuboCop::Cop::Style::RedundantFetchBlock < ::RuboCop::Cop::Cop
+  include(::RuboCop::Cop::FrozenStringLiteral)
+  include(::RuboCop::Cop::RangeHelp)
+
+  def autocorrect(node); end
+  def on_block(node); end
+  def redundant_fetch_block_candidate?(node = _); end
+
+  private
+
+  def basic_literal?(node); end
+  def build_bad_method(send, body); end
+  def build_good_method(send, body); end
+  def check_for_constant?; end
+  def check_for_string?; end
+  def fetch_range(send, node); end
+end
+
+RuboCop::Cop::Style::RedundantFetchBlock::MSG = T.let(T.unsafe(nil), String)
+
 class RuboCop::Cop::Style::RedundantFreeze < ::RuboCop::Cop::Cop
   include(::RuboCop::Cop::FrozenStringLiteral)
 
@@ -8201,10 +8257,9 @@ class RuboCop::Cop::Style::RedundantRegexpEscape < ::RuboCop::Cop::Cop
   private
 
   def allowed_escape?(node, char, within_character_class); end
+  def delimiter?(node, char); end
   def each_escape(node); end
   def escape_range_at_index(node, index); end
-  def pattern_source(node); end
-  def slash_literal?(node); end
 end
 
 RuboCop::Cop::Style::RedundantRegexpEscape::ALLOWED_ALWAYS_ESCAPES = T.let(T.unsafe(nil), Array)
@@ -8266,7 +8321,6 @@ class RuboCop::Cop::Style::RedundantSelf < ::RuboCop::Cop::Cop
   def add_scope(node, local_variables = _); end
   def allow_self(node); end
   def allowed_send_node?(node); end
-  def keyword?(method_name); end
   def on_argument(node); end
   def regular_method_call?(node); end
 
@@ -8275,6 +8329,8 @@ end
 
 RuboCop::Cop::Style::RedundantSelf::KERNEL_METHODS = T.let(T.unsafe(nil), Array)
 
+RuboCop::Cop::Style::RedundantSelf::KEYWORDS = T.let(T.unsafe(nil), Array)
+
 RuboCop::Cop::Style::RedundantSelf::MSG = T.let(T.unsafe(nil), String)
 
 class RuboCop::Cop::Style::RedundantSort < ::RuboCop::Cop::Cop
@@ -8699,8 +8755,15 @@ end
 RuboCop::Cop::Style::Strip::MSG = T.let(T.unsafe(nil), String)
 
 class RuboCop::Cop::Style::StructInheritance < ::RuboCop::Cop::Cop
+  include(::RuboCop::Cop::RangeHelp)
+
+  def autocorrect(node); end
   def on_class(node); end
   def struct_constructor?(node = _); end
+
+  private
+
+  def correct_parent(parent, corrector); end
 end
 
 RuboCop::Cop::Style::StructInheritance::MSG = T.let(T.unsafe(nil), String)
@@ -9066,6 +9129,7 @@ class RuboCop::Cop::Style::YodaCondition < ::RuboCop::Cop::Cop
   def corrected_code(node); end
   def enforce_yoda?; end
   def equality_only?; end
+  def interpolation?(node); end
   def message(node); end
   def non_equality_operator?(node); end
   def noncommutative_operator?(node); end
diff --git a/Library/Homebrew/sorbet/rbi/hidden-definitions/hidden.rbi b/Library/Homebrew/sorbet/rbi/hidden-definitions/hidden.rbi
index 1280eff6e2..096dbce314 100644
--- a/Library/Homebrew/sorbet/rbi/hidden-definitions/hidden.rbi
+++ b/Library/Homebrew/sorbet/rbi/hidden-definitions/hidden.rbi
@@ -13558,26 +13558,6 @@ end
 
 ParseError = Racc::ParseError
 
-class Parser::AST::Processor
-  def on_find_pattern(node); end
-
-  def on_forward_arg(node); end
-end
-
-class Parser::Builders::Default
-  def find_pattern(lbrack_t, elements, rbrack_t); end
-
-  def forward_arg(dots_t); end
-
-  def forward_only_args(begin_t, dots_t, end_t); end
-end
-
-class Parser::Builders::Default
-  def self.emit_forward_arg(); end
-
-  def self.emit_forward_arg=(emit_forward_arg); end
-end
-
 Parser::CurrentRuby = Parser::Ruby26
 
 class Parser::Ruby24
@@ -15344,22 +15324,6 @@ end
 class Parser::Ruby26
 end
 
-class Parser::Source::TreeRewriter
-  def as_nested_actions(); end
-
-  def as_replacements(); end
-
-  def import!(foreign_rewriter, offset: T.unsafe(nil)); end
-end
-
-class Parser::Source::TreeRewriter::Action
-  def contract(); end
-
-  def moved(source_buffer, offset); end
-
-  def nested_actions(); end
-end
-
 class Pathname
   include ::MachOShim
   def fnmatch?(*_); end
@@ -24484,8 +24448,6 @@ module Tins::SexySingleton
   def dup(); end
 end
 
-Tins::SexySingleton::SingletonClassMethods = Singleton::SingletonClassMethods
-
 module Tins::SexySingleton
   def self.__init__(klass); end
 
diff --git a/Library/Homebrew/test/cask/cmd/info_spec.rb b/Library/Homebrew/test/cask/cmd/info_spec.rb
index 7d529f7112..ea3385dc52 100644
--- a/Library/Homebrew/test/cask/cmd/info_spec.rb
+++ b/Library/Homebrew/test/cask/cmd/info_spec.rb
@@ -15,7 +15,7 @@ describe Cask::Cmd::Info, :cask do
       local-caffeine: 1.2.3
       https://brew.sh/
       Not installed
-      From: https://github.com/Homebrew/homebrew-cask/blob/master/Casks/local-caffeine.rb
+      From: https://github.com/Homebrew/homebrew-cask/blob/HEAD/Casks/local-caffeine.rb
       ==> Name
       None
       ==> Artifacts
@@ -30,7 +30,7 @@ describe Cask::Cmd::Info, :cask do
       with-auto-updates: 1.0 (auto_updates)
       https://brew.sh/autoupdates
       Not installed
-      From: https://github.com/Homebrew/homebrew-cask/blob/master/Casks/with-auto-updates.rb
+      From: https://github.com/Homebrew/homebrew-cask/blob/HEAD/Casks/with-auto-updates.rb
       ==> Name
       AutoUpdates
       ==> Artifacts
@@ -44,7 +44,7 @@ describe Cask::Cmd::Info, :cask do
         local-caffeine: 1.2.3
         https://brew.sh/
         Not installed
-        From: https://github.com/Homebrew/homebrew-cask/blob/master/Casks/local-caffeine.rb
+        From: https://github.com/Homebrew/homebrew-cask/blob/HEAD/Casks/local-caffeine.rb
         ==> Name
         None
         ==> Artifacts
@@ -53,7 +53,7 @@ describe Cask::Cmd::Info, :cask do
         local-transmission: 2.61
         https://brew.sh/
         Not installed
-        From: https://github.com/Homebrew/homebrew-cask/blob/master/Casks/local-transmission.rb
+        From: https://github.com/Homebrew/homebrew-cask/blob/HEAD/Casks/local-transmission.rb
         ==> Name
         Transmission
         ==> Artifacts
@@ -75,7 +75,7 @@ describe Cask::Cmd::Info, :cask do
       with-caveats: 1.2.3
       https://brew.sh/
       Not installed
-      From: https://github.com/Homebrew/homebrew-cask/blob/master/Casks/with-caveats.rb
+      From: https://github.com/Homebrew/homebrew-cask/blob/HEAD/Casks/with-caveats.rb
       ==> Name
       None
       ==> Artifacts
@@ -100,7 +100,7 @@ describe Cask::Cmd::Info, :cask do
       with-conditional-caveats: 1.2.3
       https://brew.sh/
       Not installed
-      From: https://github.com/Homebrew/homebrew-cask/blob/master/Casks/with-conditional-caveats.rb
+      From: https://github.com/Homebrew/homebrew-cask/blob/HEAD/Casks/with-conditional-caveats.rb
       ==> Name
       None
       ==> Artifacts
@@ -115,7 +115,7 @@ describe Cask::Cmd::Info, :cask do
       with-languages: 1.2.3
       https://brew.sh/
       Not installed
-      From: https://github.com/Homebrew/homebrew-cask/blob/master/Casks/with-languages.rb
+      From: https://github.com/Homebrew/homebrew-cask/blob/HEAD/Casks/with-languages.rb
       ==> Name
       None
       ==> Languages
@@ -132,7 +132,7 @@ describe Cask::Cmd::Info, :cask do
       without-languages: 1.2.3
       https://brew.sh/
       Not installed
-      From: https://github.com/Homebrew/homebrew-cask/blob/master/Casks/without-languages.rb
+      From: https://github.com/Homebrew/homebrew-cask/blob/HEAD/Casks/without-languages.rb
       ==> Name
       None
       ==> Artifacts
diff --git a/Library/Homebrew/test/cmd/info_spec.rb b/Library/Homebrew/test/cmd/info_spec.rb
index a4c64ca35d..668548fb7f 100644
--- a/Library/Homebrew/test/cmd/info_spec.rb
+++ b/Library/Homebrew/test/cmd/info_spec.rb
@@ -24,13 +24,13 @@ describe Homebrew do
 
   specify "::github_remote_path" do
     expect(subject.github_remote_path(remote, "Formula/git.rb"))
-      .to eq("https://github.com/Homebrew/homebrew-core/blob/master/Formula/git.rb")
+      .to eq("https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/git.rb")
 
     expect(subject.github_remote_path("#{remote}.git", "Formula/git.rb"))
-      .to eq("https://github.com/Homebrew/homebrew-core/blob/master/Formula/git.rb")
+      .to eq("https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/git.rb")
 
     expect(subject.github_remote_path("git@github.com:user/repo", "foo.rb"))
-      .to eq("https://github.com/user/repo/blob/master/foo.rb")
+      .to eq("https://github.com/user/repo/blob/HEAD/foo.rb")
 
     expect(subject.github_remote_path("https://mywebsite.com", "foo/bar.rb"))
       .to eq("https://mywebsite.com/foo/bar.rb")
diff --git a/Library/Homebrew/test/rubocops/cask/homepage_matches_url_spec.rb b/Library/Homebrew/test/rubocops/cask/homepage_matches_url_spec.rb
index 05c32ba66c..dd175cb4fc 100644
--- a/Library/Homebrew/test/rubocops/cask/homepage_matches_url_spec.rb
+++ b/Library/Homebrew/test/rubocops/cask/homepage_matches_url_spec.rb
@@ -110,7 +110,7 @@ describe RuboCop::Cop::Cask::HomepageMatchesUrl do
         [{
           message:  "`# brew.sh was verified as official` does not " \
                    "match the expected comment format. For details, see " \
-                  "https://github.com/Homebrew/homebrew-cask/blob/master/doc/" \
+                  "https://github.com/Homebrew/homebrew-cask/blob/HEAD/doc/" \
                   "cask_language_reference/stanzas/url.md#when-url-and-homepage-hostnames-differ-add-a-comment",
           severity: :convention,
           line:     2,
@@ -188,7 +188,7 @@ describe RuboCop::Cop::Cask::HomepageMatchesUrl do
         [{
           message:  "`brew.sh` does not match `example.org`, a comment " \
                    "has to be added above the `url` stanza. For details, see " \
-                   "https://github.com/Homebrew/homebrew-cask/blob/master/doc/" \
+                   "https://github.com/Homebrew/homebrew-cask/blob/HEAD/doc/" \
                    "cask_language_reference/stanzas/url.md#when-url-and-homepage-hostnames-differ-add-a-comment",
           severity: :convention,
           line:     2,
diff --git a/Library/Homebrew/test/support/fixtures/bottles/testball_bottle-0.1.big_sur.bottle.tar.gz b/Library/Homebrew/test/support/fixtures/bottles/testball_bottle-0.1.big_sur.bottle.tar.gz
new file mode 120000
index 0000000000..3e989830ba
--- /dev/null
+++ b/Library/Homebrew/test/support/fixtures/bottles/testball_bottle-0.1.big_sur.bottle.tar.gz
@@ -0,0 +1 @@
+testball_bottle-0.1.yosemite.bottle.tar.gz
\ No newline at end of file
diff --git a/Library/Homebrew/test/support/fixtures/bottles/testball_bottle-0.1.big_sur_arm.bottle.tar.gz b/Library/Homebrew/test/support/fixtures/bottles/testball_bottle-0.1.big_sur_arm.bottle.tar.gz
new file mode 120000
index 0000000000..3e989830ba
--- /dev/null
+++ b/Library/Homebrew/test/support/fixtures/bottles/testball_bottle-0.1.big_sur_arm.bottle.tar.gz
@@ -0,0 +1 @@
+testball_bottle-0.1.yosemite.bottle.tar.gz
\ No newline at end of file
diff --git a/Library/Homebrew/utils.rb b/Library/Homebrew/utils.rb
index 3ddf50c79c..254ac11ea1 100644
--- a/Library/Homebrew/utils.rb
+++ b/Library/Homebrew/utils.rb
@@ -497,7 +497,7 @@ module Kernel
     path.read
         .lines
         .grep(/^#:/)
-        .map { |line| line.slice(2..-1) }
+        .map { |line| line.slice(2..-1).delete_prefix("  ") }
   end
 
   def redact_secrets(input, secrets)
diff --git a/README.md b/README.md
index e770c93b21..5270a44b8d 100644
--- a/README.md
+++ b/README.md
@@ -19,7 +19,7 @@ Second, read the [Troubleshooting Checklist](https://docs.brew.sh/Troubleshootin
 **If you don't read these it will take us far longer to help you with your problem.**
 
 ## Contributing
-We'd love you to contribute to Homebrew. First, please read our [Contribution Guide](CONTRIBUTING.md) and [Code of Conduct](https://github.com/Homebrew/.github/blob/master/CODE_OF_CONDUCT.md#code-of-conduct).
+We'd love you to contribute to Homebrew. First, please read our [Contribution Guide](CONTRIBUTING.md) and [Code of Conduct](https://github.com/Homebrew/.github/blob/HEAD/CODE_OF_CONDUCT.md#code-of-conduct).
 
 We explicitly welcome contributions from people who have never contributed to open-source before: we were all beginners once! We can help build on a partially working pull request with the aim of getting it merged. We are also actively seeking to diversify our contributors and especially welcome contributions from women from all backgrounds and people of colour.
 
diff --git a/completions/bash/brew b/completions/bash/brew
index b92b594acd..1a57828607 100644
--- a/completions/bash/brew
+++ b/completions/bash/brew
@@ -162,6 +162,7 @@ _brew_create() {
       --HEAD
       --autotools
       --cmake
+      --crystal
       --debug
       --force
       --go
diff --git a/docs/Analytics.md b/docs/Analytics.md
index 009038505a..b212362818 100644
--- a/docs/Analytics.md
+++ b/docs/Analytics.md
@@ -45,7 +45,7 @@ Homebrew's analytics are sent throughout Homebrew's execution to Google Analytic
 Summaries of installation and error analytics are publicly available [here](https://brew.sh/analytics/). A JSON API is also available.
 
 ## How?
-The code is viewable in [`analytics.rb`](https://github.com/Homebrew/brew/blob/master/Library/Homebrew/utils/analytics.rb) and [`analytics.sh`](https://github.com/Homebrew/brew/blob/master/Library/Homebrew/utils/analytics.sh). They are done in a separate background process and fail fast to avoid delaying any execution. They will fail immediately and silently if you have no network connection.
+The code is viewable in [`analytics.rb`](https://github.com/Homebrew/brew/blob/HEAD/Library/Homebrew/utils/analytics.rb) and [`analytics.sh`](https://github.com/Homebrew/brew/blob/HEAD/Library/Homebrew/utils/analytics.sh). They are done in a separate background process and fail fast to avoid delaying any execution. They will fail immediately and silently if you have no network connection.
 
 ## Opting out
 Homebrew analytics helps us maintainers and leaving it on is appreciated. However, if you want to opt out of Homebrew's analytics, you can set this variable in your environment:
diff --git a/docs/Bottles.md b/docs/Bottles.md
index 2aa9cb8342..4b1d4fa332 100644
--- a/docs/Bottles.md
+++ b/docs/Bottles.md
@@ -8,7 +8,7 @@ If a bottle is available and usable it will be downloaded and poured automatical
 Bottles will not be used if the user requests it (see above), if the formula requests it (with `pour_bottle?`), if any options are specified during installation (bottles are all compiled with default options), if the bottle is not up to date (e.g. lacking a checksum) or if the bottle's `cellar` is not `:any` nor equal to the current `HOMEBREW_CELLAR`.
 
 ## Creation
-Bottles are created using the [Brew Test Bot](Brew-Test-Bot.md). This happens mostly when people submit pull requests to Homebrew and the `bottle do` block is updated by maintainers when they `brew pr-publish` or `brew pr-pull` the contents of a pull request. For the Homebrew organisations' taps they are uploaded to and downloaded from [Bintray](https://bintray.com/homebrew).
+Bottles are created using the [Brew Test Bot](Brew-Test-Bot.md), usually when people submit pull requests to Homebrew. The `bottle do` block is updated by maintainers when they merge a pull request. For the Homebrew organisations' taps they are uploaded to and downloaded from [Bintray](https://bintray.com/homebrew).
 
 By default, bottles will be built for the oldest CPU supported by the OS/architecture you're building for (Core 2 for 64-bit OSs). This ensures that bottles are compatible with all computers you might distribute them to. If you *really* want your bottles to be optimised for something else, you can pass the `--bottle-arch=` option to build for another architecture; for example, `brew install foo --build-bottle --bottle-arch=penryn`. Just remember that if you build for a newer architecture some of your users might get binaries they can't run and that would be sad!
 
diff --git a/docs/Brew-Test-Bot-For-Core-Contributors.md b/docs/Brew-Test-Bot-For-Core-Contributors.md
index cdff7164c6..5d4665e8b8 100644
--- a/docs/Brew-Test-Bot-For-Core-Contributors.md
+++ b/docs/Brew-Test-Bot-For-Core-Contributors.md
@@ -8,6 +8,7 @@ If a pull request is correct and doesn't need any modifications to commit messag
 
 1. Ensure the job has already completed successfully.
 2. Run `brew pr-publish 12345` where `12345` is the pull request number (or URL).
+    - Approving a PR for an existing formula will automatically publish the bottles and close the PR, taking care of this step.
 3. Watch the [actions queue](https://github.com/Homebrew/homebrew-core/actions) to ensure your job finishes. BrewTestBot will usually notify you of failures with a ping as well.
 
 If a pull request needs changes to the commit messages:
diff --git a/docs/External-Commands.md b/docs/External-Commands.md
index f8030d88e7..c493858291 100644
--- a/docs/External-Commands.md
+++ b/docs/External-Commands.md
@@ -39,7 +39,7 @@ For example, see the [header of `brew-services.rb`](https://github.com/Homebrew/
 
 ### homebrew-livecheck
 Check if there is a new upstream version of a formula.
-See the [`README`](https://github.com/Homebrew/homebrew-livecheck/blob/master/README.md) for more info and usage.
+See the [`README`](https://github.com/Homebrew/homebrew-livecheck/blob/HEAD/README.md) for more info and usage.
 
 Install using:
 
@@ -49,7 +49,7 @@ brew tap homebrew/livecheck
 
 ### homebrew-command-not-found
 Ubuntu's `command-not-found equivalent` for Homebrew.
-See the [`README`](https://github.com/Homebrew/homebrew-command-not-found/blob/master/README.md) for more info and usage.
+See the [`README`](https://github.com/Homebrew/homebrew-command-not-found/blob/HEAD/README.md) for more info and usage.
 
 Install using:
 
@@ -59,7 +59,7 @@ brew tap homebrew/command-not-found
 
 ### homebrew-aliases
 Allows you to alias your Homebrew commands.
-See the [`README`](https://github.com/Homebrew/homebrew-aliases/blob/master/README.md) for more info and usage.
+See the [`README`](https://github.com/Homebrew/homebrew-aliases/blob/HEAD/README.md) for more info and usage.
 
 Install using:
 
diff --git a/docs/FAQ.md b/docs/FAQ.md
index d776a3d734..9c7d26867c 100644
--- a/docs/FAQ.md
+++ b/docs/FAQ.md
@@ -74,7 +74,7 @@ the launchctl PATH for *all users*. For earlier versions of macOS, see
 [this page](https://developer.apple.com/legacy/library/qa/qa1067/_index.html).
 
 ## How do I contribute to Homebrew?
-Read our [contribution guidelines](https://github.com/Homebrew/brew/blob/master/CONTRIBUTING.md#contributing-to-homebrew).
+Read our [contribution guidelines](https://github.com/Homebrew/brew/blob/HEAD/CONTRIBUTING.md#contributing-to-homebrew).
 
 ## Why do you compile everything?
 Homebrew provides pre-compiled versions for many formulae. These
diff --git a/docs/Formula-Cookbook.md b/docs/Formula-Cookbook.md
index 242899eb1e..ac475face9 100644
--- a/docs/Formula-Cookbook.md
+++ b/docs/Formula-Cookbook.md
@@ -21,7 +21,7 @@ Homebrew uses Git for downloading updates and contributing to the project.
 
 Homebrew installs to the `Cellar` and then symlinks some of the installation into `/usr/local` so that other programs can see what's going on. We suggest you `brew ls` a few of the kegs in your Cellar to see how it is all arranged.
 
-Packages are installed according to their formulae, which live in `/usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/Formula`. Check out a simple one, e.g. `brew edit etl` (or [`etl`](https://github.com/Homebrew/homebrew-core/blob/master/Formula/etl.rb)) or a more advanced one, e.g. `brew edit git` (or [`git`](https://github.com/Homebrew/homebrew-core/blob/master/Formula/git.rb)).
+Packages are installed according to their formulae, which live in `/usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/Formula`. Check out a simple one, e.g. `brew edit etl` (or [`etl`](https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/etl.rb)) or a more advanced one, e.g. `brew edit git` (or [`git`](https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/git.rb)).
 
 ## Basic instructions
 
@@ -36,7 +36,7 @@ Before submitting a new formula make sure your package:
 * has a stable, tagged version (i.e. not just a GitHub repository with no versions)
 * passes all `brew audit --new-formula <formula>` tests
 
-Before submitting a new formula make sure you read over our [contribution guidelines](https://github.com/Homebrew/brew/blob/master/CONTRIBUTING.md#contributing-to-homebrew).
+Before submitting a new formula make sure you read over our [contribution guidelines](https://github.com/Homebrew/brew/blob/HEAD/CONTRIBUTING.md#contributing-to-homebrew).
 
 ### Grab the URL
 
@@ -121,7 +121,7 @@ to avoid conflicting with the system so sometimes formulae need to
 have environment variables set or special configuration flags passed
 to locate our OpenSSL. You can see this mechanism in the
 [`clamav`](https://github.com/Homebrew/homebrew-core/blob/89c4574ef1a6d15e92196637ff315a0a4bb3e289/Formula/clamav.rb#L37)
-formula. Usually this is unnecessary because Homebrew sets up our [build environment](https://github.com/Homebrew/brew/blob/master/Library/Homebrew/extend/ENV/super.rb)
+formula. Usually this is unnecessary because Homebrew sets up our [build environment](https://github.com/Homebrew/brew/blob/HEAD/Library/Homebrew/extend/ENV/super.rb)
 to favour finding [`keg_only`](https://rubydoc.brew.sh/Formula#keg_only-class_method) formulae first.
 
 **Important:** `$(brew --prefix)/bin` is NOT on the `PATH` during formula installation. If you have dependencies at build time, you must specify them and `brew` will add them to the `PATH` or create a [`Requirement`](https://rubydoc.brew.sh/Requirement).
@@ -168,9 +168,9 @@ description can be overridden using the normal option syntax (in this case, the
 
 Sometimes there’s hard conflict between formulae, and it can’t be avoided or circumvented with [`keg_only`](https://rubydoc.brew.sh/Formula#keg_only-class_method).
 
-A good example formula for minor conflict is [`mbedtls`](https://github.com/Homebrew/homebrew-core/blob/master/Formula/mbedtls.rb), which ships and compiles a "Hello World" executable. This is obviously non-essential to `mbedtls`’s functionality, and conflict with the popular GNU [`hello`](https://github.com/Homebrew/homebrew-core/blob/master/Formula/hello.rb) formula would be overkill, so we just [remove it](https://github.com/Homebrew/homebrew-core/blob/966273060ad507fea490bd931971963de8b1a1dc/Formula/mbedtls.rb#L30-L31) during the installation process.
+A good example formula for minor conflict is [`mbedtls`](https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/mbedtls.rb), which ships and compiles a "Hello World" executable. This is obviously non-essential to `mbedtls`’s functionality, and conflict with the popular GNU [`hello`](https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/hello.rb) formula would be overkill, so we just [remove it](https://github.com/Homebrew/homebrew-core/blob/966273060ad507fea490bd931971963de8b1a1dc/Formula/mbedtls.rb#L30-L31) during the installation process.
 
-[`pdftohtml`](https://github.com/Homebrew/homebrew-core/blob/master/Formula/pdftohtml.rb) provides an example of a serious
+[`pdftohtml`](https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/pdftohtml.rb) provides an example of a serious
 conflict, where both formula ship an identically-named binary that is essential to functionality, so a [`conflicts_with`](https://rubydoc.brew.sh/Formula#conflicts_with-class_method) is preferable.
 
 As a general rule, [`conflicts_with`](https://rubydoc.brew.sh/Formula#conflicts_with-class_method) should be a last-resort option. It’s a fairly blunt instrument.
@@ -235,7 +235,7 @@ class Foo < Formula
 end
 ```
 
-[`jrnl`](https://github.com/Homebrew/homebrew-core/blob/master/Formula/jrnl.rb) is an example of a formula that does this well. The end result means the user doesn't have to use `pip` or Python and can just run `jrnl`.
+[`jrnl`](https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/jrnl.rb) is an example of a formula that does this well. The end result means the user doesn't have to use `pip` or Python and can just run `jrnl`.
 
 [homebrew-pypi-poet](https://github.com/tdsmith/homebrew-pypi-poet) can help you generate [`resource`](https://rubydoc.brew.sh/Formula#resource-class_method) stanzas for the dependencies of your Python application.
 
@@ -259,9 +259,9 @@ function. The environment variable `HOME` is set to [`testpath`](https://rubydoc
 
 We want tests that don't require any user input and test the basic functionality of the application. For example `foo build-foo input.foo` is a good test and (despite their widespread use) `foo --version` and `foo --help` are bad tests. However, a bad test is better than no test at all.
 
-See [`cmake`](https://github.com/Homebrew/homebrew-core/blob/master/Formula/cmake.rb) for an example of a formula with a good test. The formula writes a basic `CMakeLists.txt` file into the test directory then calls CMake to generate Makefiles. This test checks that CMake doesn't e.g. segfault during basic operation.
+See [`cmake`](https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/cmake.rb) for an example of a formula with a good test. The formula writes a basic `CMakeLists.txt` file into the test directory then calls CMake to generate Makefiles. This test checks that CMake doesn't e.g. segfault during basic operation.
 
-You can check that the output is as expected with `assert_equal` or `assert_match` on the output of shell_output such as in this example from the [envv formula](https://github.com/Homebrew/homebrew-core/blob/master/Formula/envv.rb):
+You can check that the output is as expected with `assert_equal` or `assert_match` on the output of shell_output such as in this example from the [envv formula](https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/envv.rb):
 
 ```ruby
 assert_equal "mylist=A:C; export mylist", shell_output("#{bin}/envv del mylist B").strip
@@ -275,7 +275,7 @@ assert_predicate testpath/"output.txt", :exist?
 
 Some advice for specific cases:
 * If the formula is a library, compile and run some simple code that links against it. It could be taken from upstream's documentation / source examples.
-A good example is [`tinyxml2`](https://github.com/Homebrew/homebrew-core/blob/master/Formula/tinyxml2.rb), which writes a small C++ source file into the test directory, compiles and links it against the tinyxml2 library and finally checks that the resulting program runs successfully.
+A good example is [`tinyxml2`](https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/tinyxml2.rb), which writes a small C++ source file into the test directory, compiles and links it against the tinyxml2 library and finally checks that the resulting program runs successfully.
 * If the formula is for a GUI program, try to find some function that runs as command-line only, like a format conversion, reading or displaying a config file, etc.
 * If the software cannot function without credentials or requires a virtual machine, docker instance, etc. to run, a test could be to try to connect with invalid credentials (or without credentials) and confirm that it fails as expected. This is prefered over mocking a dependency.
 * Homebrew comes with a number of [standard test fixtures](https://github.com/Homebrew/brew/tree/master/Library/Homebrew/test/support/fixtures), including numerous sample images, sounds, and documents in various formats. You can get the file path to a test fixture with `test_fixtures("test.svg")`.
@@ -322,7 +322,7 @@ If you’re not sure about the name, check its homepage, Wikipedia page and [wha
 
 When Homebrew already has a formula called `foo` we typically do not accept requests to replace that formula with something else also named `foo`. This is to avoid both confusing and surprising users’ expectations.
 
-When two formulae share an upstream name, e.g. [AESCrypt](https://github.com/Homebrew/homebrew-core/blob/master/Formula/aescrypt.rb) and [AES Crypt](https://github.com/Homebrew/homebrew-core/blob/master/Formula/aescrypt-packetizer.rb) the newer formula must typically adapt its name to avoid conflict with the current formula.
+When two formulae share an upstream name, e.g. [AESCrypt](https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/aescrypt.rb) and [AES Crypt](https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/aescrypt-packetizer.rb) the newer formula must typically adapt its name to avoid conflict with the current formula.
 
 If you’re *still* not sure, just commit. We’ll apply some arbitrary rule and make a decision 😉.
 
@@ -740,9 +740,9 @@ Homebrew provides two formula DSL methods for launchd plist files:
 
 Homebrew has multiple levels of environment variable filtering which affects variables available to formulae.
 
-Firstly, the overall environment in which Homebrew runs is filtered to avoid environment contamination breaking from-source builds (<https://github.com/Homebrew/brew/issues/932>). In particular, this process filters all but the given whitelisted variables, but allows environment variables prefixed with `HOMEBREW_`. The specific implementation can be seen in [`bin/brew`](https://github.com/Homebrew/brew/blob/master/bin/brew).
+Firstly, the overall environment in which Homebrew runs is filtered to avoid environment contamination breaking from-source builds (<https://github.com/Homebrew/brew/issues/932>). In particular, this process filters all but the given whitelisted variables, but allows environment variables prefixed with `HOMEBREW_`. The specific implementation can be seen in [`bin/brew`](https://github.com/Homebrew/brew/blob/HEAD/bin/brew).
 
-The second level of filtering removes sensitive environment variables (such as credentials like keys, passwords or tokens) to avoid malicious subprocesses obtaining them (<https://github.com/Homebrew/brew/pull/2524>). This has the effect of preventing any such variables from reaching a formula's Ruby code as they are filtered before it is called. The specific implementation can be seen in the [`ENV.clear_sensitive_environment!` method](https://github.com/Homebrew/brew/blob/master/Library/Homebrew/extend/ENV.rb).
+The second level of filtering removes sensitive environment variables (such as credentials like keys, passwords or tokens) to avoid malicious subprocesses obtaining them (<https://github.com/Homebrew/brew/pull/2524>). This has the effect of preventing any such variables from reaching a formula's Ruby code as they are filtered before it is called. The specific implementation can be seen in the [`ENV.clear_sensitive_environment!` method](https://github.com/Homebrew/brew/blob/HEAD/Library/Homebrew/extend/ENV.rb).
 
 In summary, environment variables used by a formula need to conform to these filtering rules in order to be available.
 
diff --git a/docs/Homebrew-Governance.md b/docs/Homebrew-Governance.md
index 35f0391ce3..9283faa14f 100644
--- a/docs/Homebrew-Governance.md
+++ b/docs/Homebrew-Governance.md
@@ -16,7 +16,7 @@
 
 4. Members may be dismissed by majority vote of the Project Leadership Committee and removed from the Homebrew organisation on GitHub. Removed members may be reinstated by the usual admission process.
 
-5. All members will follow the [Homebrew Code of Conduct](https://github.com/Homebrew/.github/blob/master/CODE_OF_CONDUCT.md#code-of-conduct). Changes to the code of conduct must be approved by the PLC.
+5. All members will follow the [Homebrew Code of Conduct](https://github.com/Homebrew/.github/blob/HEAD/CODE_OF_CONDUCT.md#code-of-conduct). Changes to the code of conduct must be approved by the PLC.
 
 6. Homebrew members will comply with the Software Freedom Conservancy's [conflict of interest policy](https://sfconservancy.org/projects/policies/conflict-of-interest-policy.html).
 
diff --git a/docs/Homebrew-homebrew-core-Merge-Checklist.md b/docs/Homebrew-homebrew-core-Merge-Checklist.md
index 3f2dc6569e..3ee396815f 100644
--- a/docs/Homebrew-homebrew-core-Merge-Checklist.md
+++ b/docs/Homebrew-homebrew-core-Merge-Checklist.md
@@ -54,7 +54,7 @@ Check for:
 - if CI is green and...
   - formula `bottle :unneeded`, you can merge it through GitHub UI
   - bottles need to be pulled, and...
-    - the commits are correct and don't need changes, use: `brew pr-publish $PR_ID`
+    - the commits are correct and don't need changes, approve the PR to trigger an automatic merge (use `brew pr-publish $PR_ID` to trigger manually in case of a new formula)
     - the commits need to be amended, use `brew pr-pull $PR_ID`, make changes, and `git push`
 - don't forget to thank the contributor
   - celebrate the first-time contributors
diff --git a/docs/Homebrew-linuxbrew-core-Maintainer-Guide.md b/docs/Homebrew-linuxbrew-core-Maintainer-Guide.md
index 29f2e9d0af..74a5c858a4 100644
--- a/docs/Homebrew-linuxbrew-core-Maintainer-Guide.md
+++ b/docs/Homebrew-linuxbrew-core-Maintainer-Guide.md
@@ -341,7 +341,7 @@ correct repository:
 
 > Thanks for your PR.
 >
-> However, this formula is not Linux-specific. Its new versions are merged from the [Homebrew/homebrew-core](https://github.com/Homebrew/homebrew-core) repository daily [as documented in CONTRIBUTING.md](https://github.com/Homebrew/linuxbrew-core/blob/master/CONTRIBUTING.md). Please submit this change as a PR to that repository.
+> However, this formula is not Linux-specific. Its new versions are merged from the [Homebrew/homebrew-core](https://github.com/Homebrew/homebrew-core) repository daily [as documented in CONTRIBUTING.md](https://github.com/Homebrew/linuxbrew-core/blob/HEAD/CONTRIBUTING.md). Please submit this change as a PR to that repository.
 >
 > We look forward to your PR against Homebrew/homebrew-core for the next version bump!
 
diff --git a/docs/Maintainer-Guidelines.md b/docs/Maintainer-Guidelines.md
index d6b8ac32d6..7eebe79bb8 100644
--- a/docs/Maintainer-Guidelines.md
+++ b/docs/Maintainer-Guidelines.md
@@ -165,6 +165,6 @@ All communication should ideally occur in public on GitHub. Where this is not po
 
 This makes it easier for other maintainers, contributors and users to follow along with what we're doing (and, more importantly, why we're doing it) and means that decisions have a linkable URL.
 
-All maintainers (and lead maintainer) communication through any medium is bound by [Homebrew's Code of Conduct](https://github.com/Homebrew/.github/blob/master/CODE_OF_CONDUCT.md#code-of-conduct). Abusive behaviour towards other maintainers, contributors or users will not be tolerated; the maintainer will be given a warning and if their behaviour continues they will be removed as a maintainer.
+All maintainers (and lead maintainer) communication through any medium is bound by [Homebrew's Code of Conduct](https://github.com/Homebrew/.github/blob/HEAD/CODE_OF_CONDUCT.md#code-of-conduct). Abusive behaviour towards other maintainers, contributors or users will not be tolerated; the maintainer will be given a warning and if their behaviour continues they will be removed as a maintainer.
 
 Maintainers should feel free to pleasantly disagree with the work and decisions of other maintainers. Healthy, friendly, technical disagreement between maintainers is actively encouraged and should occur in public on the issue tracker to make the project better. Interpersonal issues should be handled privately in Slack, ideally with moderation. If work or decisions are insufficiently documented or explained any maintainer or contributor should feel free to ask for clarification. No maintainer may ever justify a decision with e.g. "because I say so" or "it was I who did X" alone. Off-topic discussions on the issue tracker, [bike-shedding](https://en.wikipedia.org/wiki/Law_of_triviality) and personal attacks are forbidden.
diff --git a/docs/Manpage.md b/docs/Manpage.md
index 0acac0de49..5c36232648 100644
--- a/docs/Manpage.md
+++ b/docs/Manpage.md
@@ -588,9 +588,9 @@ If *`formula`* is provided, display the file or directory used to cache *`formul
 * `--force-bottle`:
   Show the cache file used when pouring a bottle.
 * `--formula`:
-  Show cache files for only formulae
+  Only show cache files for formulae.
 * `--cask`:
-  Show cache files for only casks
+  Only show cache files for casks.
 
 ### `--cellar` [*`formula`*]
 
@@ -769,6 +769,8 @@ a simple example. For the complete API, see:
   Create a basic template for an Autotools-style build.
 * `--cmake`:
   Create a basic template for a CMake-style build.
+* `--crystal`:
+  Create a basic template for a Crystal build.
 * `--go`:
   Create a basic template for a Go build.
 * `--meson`:
@@ -898,17 +900,17 @@ repository.
 * `--resolve`:
   When a patch fails to apply, leave in progress and allow user to resolve, instead of aborting.
 * `--workflow`:
-  Retrieve artifacts from the specified workflow (default: tests.yml).
+  Retrieve artifacts from the specified workflow (default: `tests.yml`).
 * `--artifact`:
-  Download artifacts with the specified name (default: bottles).
+  Download artifacts with the specified name (default: `bottles`).
 * `--bintray-org`:
-  Upload to the specified Bintray organisation (default: homebrew).
+  Upload to the specified Bintray organisation (default: `homebrew`).
 * `--tap`:
-  Target tap repository (default: homebrew/core).
+  Target tap repository (default: `homebrew/core`).
 * `--root-url`:
   Use the specified *`URL`* as the root of the bottle's URL instead of Homebrew's default.
 * `--bintray-mirror`:
-  Use the specified Bintray repository to automatically mirror stable URLs defined in the formulae (default: mirror)
+  Use the specified Bintray repository to automatically mirror stable URLs defined in the formulae (default: `mirror`).
 
 ### `pr-upload` [*`options`*]
 
@@ -919,7 +921,7 @@ Apply the bottle commit and publish bottles to Bintray.
 * `-n`, `--dry-run`:
   Print what would be done rather than doing it.
 * `--bintray-org`:
-  Upload to the specified Bintray organisation (default: homebrew).
+  Upload to the specified Bintray organisation (default: `homebrew`).
 * `--root-url`:
   Use the specified *`URL`* as the root of the bottle's URL instead of Homebrew's default.
 
diff --git a/docs/New-Maintainer-Checklist.md b/docs/New-Maintainer-Checklist.md
index 7a27dd3ec8..27ce7a1acd 100644
--- a/docs/New-Maintainer-Checklist.md
+++ b/docs/New-Maintainer-Checklist.md
@@ -33,9 +33,10 @@ A few requests:
 - In Homebrew/brew, close pull requests using GitHub's "Merge pull request"
   button in "Create a merge commit" mode.
 - In Homebrew/homebrew-core, use `brew pr-publish` to close pull requests
-  that require new bottles or change multiple formulae. If commits need to
-  be amended use `brew pr-pull` instead. Let these commands auto-close
-  issues whenever possible (it may take up to 5 minutes). If in doubt,
+  that require new bottles or change multiple formulae. Note that an approving
+  review on a pull request for an existing formula will trigger this automatically.
+  If commits need to be amended use `brew pr-pull` instead. Let these commands
+  auto-close issues whenever possible (it may take up to 5 minutes). If in doubt,
   check with e.g. Fork.app that you've not accidentally added merge commits.
   If bottles are unnecessary, use GitHub's "Merge pull request" button in
   "Squash and merge" mode for a single formula change.
diff --git a/docs/Python-for-Formula-Authors.md b/docs/Python-for-Formula-Authors.md
index 31a1f4b8ba..3d7318086e 100644
--- a/docs/Python-for-Formula-Authors.md
+++ b/docs/Python-for-Formula-Authors.md
@@ -2,9 +2,9 @@
 
 This document explains how to successfully use Python in a Homebrew formula.
 
-Homebrew draws a distinction between Python **applications** and Python **libraries**. The difference is that users generally do not care that applications are written in Python; it is unusual that a user would expect to be able to `import foo` after installing an application. Examples of applications are [`ansible`](https://github.com/Homebrew/homebrew-core/blob/master/Formula/ansible.rb) and [`jrnl`](https://github.com/Homebrew/homebrew-core/blob/master/Formula/jrnl.rb).
+Homebrew draws a distinction between Python **applications** and Python **libraries**. The difference is that users generally do not care that applications are written in Python; it is unusual that a user would expect to be able to `import foo` after installing an application. Examples of applications are [`ansible`](https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/ansible.rb) and [`jrnl`](https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/jrnl.rb).
 
-Python libraries exist to be imported by other Python modules; they are often dependencies of Python applications. They are usually no more than incidentally useful in a terminal. Examples of libraries are [`py2cairo`](https://github.com/Homebrew/homebrew-core/blob/master/Formula/py2cairo.rb) and the bindings that are installed by [`protobuf`](https://github.com/Homebrew/homebrew-core/blob/master/Formula/protobuf.rb).
+Python libraries exist to be imported by other Python modules; they are often dependencies of Python applications. They are usually no more than incidentally useful in a terminal. Examples of libraries are [`py2cairo`](https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/py2cairo.rb) and the bindings that are installed by [`protobuf`](https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/protobuf.rb).
 
 Bindings are a special case of libraries that allow Python code to interact with a library or application implemented in another language.
 
diff --git a/docs/Xcode.md b/docs/Xcode.md
index 1569b0d1be..a2467201ae 100644
--- a/docs/Xcode.md
+++ b/docs/Xcode.md
@@ -2,13 +2,13 @@
 
 ## Supported Xcode versions
 Homebrew supports and recommends the latest Xcode and/or Command Line
-Tools available for your platform (see `OS::Mac::Xcode.latest_version` and `OS::Mac::CLT.latest_version` in [`Library/Homebrew/os/mac/xcode.rb`](https://github.com/Homebrew/brew/blob/master/Library/Homebrew/os/mac/xcode.rb)).
+Tools available for your platform (see `OS::Mac::Xcode.latest_version` and `OS::Mac::CLT.latest_version` in [`Library/Homebrew/os/mac/xcode.rb`](https://github.com/Homebrew/brew/blob/HEAD/Library/Homebrew/os/mac/xcode.rb)).
 
 ## Updating for new Xcode releases
 When a new Xcode release is made, the following things need to be
 updated:
 
-* In [`Library/Homebrew/os/mac/xcode.rb`](https://github.com/Homebrew/brew/blob/master/Library/Homebrew/os/mac/xcode.rb)
+* In [`Library/Homebrew/os/mac/xcode.rb`](https://github.com/Homebrew/brew/blob/HEAD/Library/Homebrew/os/mac/xcode.rb)
   * `OS::Mac::Xcode.latest_version`
   * `OS::Mac::CLT.latest_version`
   * `OS::Mac::Xcode.detect_version_from_clang_version`
diff --git a/docs/vale-styles/Homebrew/Abbreviations.yml b/docs/vale-styles/Homebrew/Abbreviations.yml
index 95bd5b559e..c26a146698 100644
--- a/docs/vale-styles/Homebrew/Abbreviations.yml
+++ b/docs/vale-styles/Homebrew/Abbreviations.yml
@@ -2,7 +2,7 @@
 extends: substitution
 message: Use '%s'
 ignorecase: false
-link: 'https://github.com/Homebrew/brew/blob/master/docs/Prose-Style-Guidelines.md#style-and-usage'
+link: 'https://github.com/Homebrew/brew/blob/HEAD/docs/Prose-Style-Guidelines.md#style-and-usage'
 level: error
 nonword: true
 swap:
diff --git a/docs/vale-styles/Homebrew/OxfordComma.yml b/docs/vale-styles/Homebrew/OxfordComma.yml
index 26f258763e..4049ba328e 100644
--- a/docs/vale-styles/Homebrew/OxfordComma.yml
+++ b/docs/vale-styles/Homebrew/OxfordComma.yml
@@ -1,7 +1,7 @@
 ---
 extends: existence
 message: 'No Oxford commas!'
-link: 'https://github.com/Homebrew/brew/blob/master/docs/Prose-Style-Guidelines.md#typographical-conventions'
+link: 'https://github.com/Homebrew/brew/blob/HEAD/docs/Prose-Style-Guidelines.md#typographical-conventions'
 scope: sentence
 level: warning
 tokens:
diff --git a/docs/vale-styles/Homebrew/Pronouns.yml b/docs/vale-styles/Homebrew/Pronouns.yml
index f1d5f30c33..f980d584b2 100644
--- a/docs/vale-styles/Homebrew/Pronouns.yml
+++ b/docs/vale-styles/Homebrew/Pronouns.yml
@@ -1,7 +1,7 @@
 ---
 extends: existence
 message: Avoid gender-specific language when not necessary.
-link: 'https://github.com/Homebrew/brew/blob/master/docs/Prose-Style-Guidelines.md#personal-pronouns'
+link: 'https://github.com/Homebrew/brew/blob/HEAD/docs/Prose-Style-Guidelines.md#personal-pronouns'
 level: warning
 ignorecase: true
 tokens:
diff --git a/docs/vale-styles/Homebrew/Spacing.yml b/docs/vale-styles/Homebrew/Spacing.yml
index 2b3f2bdc10..0ee95cd5f8 100644
--- a/docs/vale-styles/Homebrew/Spacing.yml
+++ b/docs/vale-styles/Homebrew/Spacing.yml
@@ -1,7 +1,7 @@
 ---
 extends: existence
 message: "'%s' should have one space."
-link: 'https://github.com/Homebrew/brew/blob/master/docs/Prose-Style-Guidelines.md#typographical-conventions'
+link: 'https://github.com/Homebrew/brew/blob/HEAD/docs/Prose-Style-Guidelines.md#typographical-conventions'
 level: error
 nonword: true
 tokens:
diff --git a/docs/vale-styles/Homebrew/Terms.yml b/docs/vale-styles/Homebrew/Terms.yml
index 5262e5df1b..5803cdfc24 100644
--- a/docs/vale-styles/Homebrew/Terms.yml
+++ b/docs/vale-styles/Homebrew/Terms.yml
@@ -1,7 +1,7 @@
 ---
 extends: substitution
 message: Use '%s' instead of '%s'.
-link: 'https://github.com/Homebrew/brew/blob/master/docs/Prose-Style-Guidelines.md#terminology-words-and-word-styling'
+link: 'https://github.com/Homebrew/brew/blob/HEAD/docs/Prose-Style-Guidelines.md#terminology-words-and-word-styling'
 level: error
 scope: $paragraph
 swap:
diff --git a/docs/vale-styles/Homebrew/Trademarks.yml b/docs/vale-styles/Homebrew/Trademarks.yml
index e1d335d46c..869ee35332 100644
--- a/docs/vale-styles/Homebrew/Trademarks.yml
+++ b/docs/vale-styles/Homebrew/Trademarks.yml
@@ -1,7 +1,7 @@
 ---
 extends: existence
 message: 'No "TM", ™, SM, ©, ®, or other explicit indicators of rights ownership or trademarks'
-link: 'https://github.com/Homebrew/brew/blob/master/docs/Prose-Style-Guidelines.md#typographical-conventions'
+link: 'https://github.com/Homebrew/brew/blob/HEAD/docs/Prose-Style-Guidelines.md#typographical-conventions'
 level: error
 nonword: true
 tokens:
diff --git a/manpages/brew.1 b/manpages/brew.1
index ebec6a5b2f..b3ed4b1578 100644
--- a/manpages/brew.1
+++ b/manpages/brew.1
@@ -765,11 +765,11 @@ Show the cache file used when pouring a bottle\.
 .
 .TP
 \fB\-\-formula\fR
-Show cache files for only formulae
+Only show cache files for formulae\.
 .
 .TP
 \fB\-\-cask\fR
-Show cache files for only casks
+Only show cache files for casks\.
 .
 .SS "\fB\-\-cellar\fR [\fIformula\fR]"
 Display Homebrew\'s Cellar path\. \fIDefault:\fR \fB$(brew \-\-prefix)/Cellar\fR, or if that directory doesn\'t exist, \fB$(brew \-\-repository)/Cellar\fR\.
@@ -999,6 +999,10 @@ Create a basic template for an Autotools\-style build\.
 Create a basic template for a CMake\-style build\.
 .
 .TP
+\fB\-\-crystal\fR
+Create a basic template for a Crystal build\.
+.
+.TP
 \fB\-\-go\fR
 Create a basic template for a Go build\.
 .
@@ -1165,19 +1169,19 @@ When a patch fails to apply, leave in progress and allow user to resolve, instea
 .
 .TP
 \fB\-\-workflow\fR
-Retrieve artifacts from the specified workflow (default: tests\.yml)\.
+Retrieve artifacts from the specified workflow (default: \fBtests\.yml\fR)\.
 .
 .TP
 \fB\-\-artifact\fR
-Download artifacts with the specified name (default: bottles)\.
+Download artifacts with the specified name (default: \fBbottles\fR)\.
 .
 .TP
 \fB\-\-bintray\-org\fR
-Upload to the specified Bintray organisation (default: homebrew)\.
+Upload to the specified Bintray organisation (default: \fBhomebrew\fR)\.
 .
 .TP
 \fB\-\-tap\fR
-Target tap repository (default: homebrew/core)\.
+Target tap repository (default: \fBhomebrew/core\fR)\.
 .
 .TP
 \fB\-\-root\-url\fR
@@ -1185,7 +1189,7 @@ Use the specified \fIURL\fR as the root of the bottle\'s URL instead of Homebrew
 .
 .TP
 \fB\-\-bintray\-mirror\fR
-Use the specified Bintray repository to automatically mirror stable URLs defined in the formulae (default: mirror)
+Use the specified Bintray repository to automatically mirror stable URLs defined in the formulae (default: \fBmirror\fR)\.
 .
 .SS "\fBpr\-upload\fR [\fIoptions\fR]"
 Apply the bottle commit and publish bottles to Bintray\.
@@ -1200,7 +1204,7 @@ Print what would be done rather than doing it\.
 .
 .TP
 \fB\-\-bintray\-org\fR
-Upload to the specified Bintray organisation (default: homebrew)\.
+Upload to the specified Bintray organisation (default: \fBhomebrew\fR)\.
 .
 .TP
 \fB\-\-root\-url\fR