Use module Compat for everything.

Library/Homebrew/compat/ENV/shared.rb

@@ -1,4 +1,5 @@
 module SharedEnvExtension
+  module Compat
     def j1
       odisabled "ENV.j1", "ENV.deparallelize"
     end
@@ -6,4 +7,7 @@ module SharedEnvExtension
     def java_cache
       odisabled "ENV.java_cache"
     end
+  end
+
+  prepend Compat
 end

Library/Homebrew/compat/dependable.rb

@@ -1,6 +1,10 @@
 module Dependable
+  module Compat
     def run?
       odeprecated "Dependable#run?"
       tags.include? :run
     end
+  end
+
+  prepend Compat
 end

Library/Homebrew/compat/extend/string.rb

@@ -1,4 +1,5 @@
 class String
+  module Compat
     def undent
       odisabled "<<-EOS.undent", "<<~EOS"
       self
@@ -16,4 +17,7 @@ class String
     #               mollit anim id est laborum.
     #               EOS
     alias undent_________________________________________________________72 undent
+  end
+
+  prepend Compat
 end

Library/Homebrew/compat/formula.rb

@@ -1,5 +1,9 @@
 class Formula
+  module Compat
     def rake(*)
       odisabled "FileUtils#rake", "system \"rake\""
     end
+  end
+
+  prepend Compat
 end

Library/Homebrew/compat/gpg.rb

@@ -1,7 +1,6 @@
-
 module Gpg
-  module_function
-
+  class << self
+    module Compat
       def executable
         odisabled "Gpg.executable", 'which "gpg"'
       end
@@ -10,7 +9,7 @@ module Gpg
         odisabled "Gpg.available?", 'which "gpg"'
       end
 
-  def create_test_key(_)
+      def create_test_key(*)
         odisabled "Gpg.create_test_key"
       end
 
@@ -18,7 +17,11 @@ module Gpg
         odisabled "Gpg.cleanup_test_processes!"
       end
 
-  def test(_)
+      def test(*)
         odisabled "Gpg.test"
       end
+    end
+
+    prepend Compat
+  end
 end

Library/Homebrew/compat/hbc/cache.rb

@@ -1,7 +1,7 @@
 module Hbc
   module Cache
-    module_function
-
+    class << self
+      module Compat
         def delete_legacy_cache
           legacy_cache = HOMEBREW_CACHE.join("Casks")
           return unless legacy_cache.exist?
@@ -10,4 +10,8 @@ module Hbc
           FileUtils.remove_entry_secure(legacy_cache)
         end
       end
+
+      prepend Compat
+    end
+  end
 end

Library/Homebrew/compat/hbc/caskroom.rb

@@ -1,7 +1,7 @@
 module Hbc
   module Caskroom
-    module_function
-
+    class << self
+      module Compat
         def migrate_legacy_caskroom
           return if Hbc.caskroom.exist?
 
@@ -42,4 +42,8 @@ module Hbc
           end
         end
       end
+
+      prepend Compat
+    end
+  end
 end

Library/Homebrew/compat/hbc/cli/update.rb

@@ -2,6 +2,7 @@ require "cask/lib/hbc/cli/abstract_command"
 
 module Hbc
   class CLI
+    module Compat
       class Update < AbstractCommand
         def self.run(*_ignored)
           odisabled "`brew cask update`", "`brew update`"
@@ -12,4 +13,7 @@ module Hbc
         end
       end
     end
+
+    prepend Compat
+  end
 end

Library/Homebrew/compat/hbc/dsl.rb

@@ -1,7 +1,11 @@
 module Hbc
   class DSL
+    module Compat
       def license(*)
         odeprecated "Hbc::DSL#license"
       end
     end
+
+    prepend Compat
+  end
 end

Library/Homebrew/compat/os/mac.rb

@@ -1,10 +1,14 @@
 module OS
   module Mac
-    module_function
-
+    class << self
+      module Compat
         def release
           odeprecated "MacOS.release", "MacOS.version"
           version
         end
       end
+
+      prepend Compat
+    end
+  end
 end