Add commented out deprecations for MacOS when simulating Linux

Library/Homebrew/os/mac.rb

@@ -7,6 +7,9 @@ require "os/mac/xcode"
 require "os/mac/sdk"
 require "os/mac/keg"
 
+# TODO: remove this once the `MacOS` module is undefined on Linux
+require "simulate_system"
+
 module OS
   # Helper module for querying system information on macOS.
   module Mac
@@ -21,6 +24,7 @@ module OS
     # using the standard Ruby Comparable methods.
     sig { returns(MacOSVersion) }
     def self.version
+      # odeprecated "`MacOS.version` on Linux" if Homebrew::SimulateSystem.simulating_or_running_on_linux?
       @version ||= full_version.strip_patch
     end
 
@@ -28,6 +32,7 @@ module OS
     # using the standard Ruby Comparable methods.
     sig { returns(MacOSVersion) }
     def self.full_version
+      # odeprecated "`MacOS.full_version` on Linux" if Homebrew::SimulateSystem.simulating_or_running_on_linux?
       @full_version ||= if ENV["HOMEBREW_FAKE_EL_CAPITAN"] # for Portable Ruby building
         MacOSVersion.new("10.11.6")
       else
@@ -60,6 +65,7 @@ module OS
     end
 
     def self.languages
+      # odeprecated "`MacOS.languages` on Linux" if Homebrew::SimulateSystem.simulating_or_running_on_linux?
       return @languages if @languages
 
       os_langs = Utils.popen_read("defaults", "read", "-g", "AppleLanguages")
@@ -73,6 +79,7 @@ module OS
     end
 
     def self.language
+      # odeprecated "`MacOS.language` on Linux" if Homebrew::SimulateSystem.simulating_or_running_on_linux?
       languages.first
     end
 
@@ -83,6 +90,7 @@ module OS
 
     sig { returns(T::Boolean) }
     def self.sdk_root_needed?
+      # odeprecated "`MacOS.sdk_root_needed?` on Linux" if Homebrew::SimulateSystem.simulating_or_running_on_linux?
       if MacOS::CLT.installed?
         # If there's no CLT SDK, return false
         return false unless MacOS::CLT.provides_sdk?
@@ -131,11 +139,13 @@ module OS
 
     # Returns the path to an SDK or nil, following the rules set by {sdk}.
     def self.sdk_path(version = nil)
+      # odeprecated "`MacOS.sdk_path` on Linux" if Homebrew::SimulateSystem.simulating_or_running_on_linux?
       s = sdk(version)
       s&.path
     end
 
     def self.sdk_path_if_needed(version = nil)
+      # odeprecated "`MacOS.sdk_path_if_needed` on Linux" if Homebrew::SimulateSystem.simulating_or_running_on_linux?
       # Prefer CLT SDK when both Xcode and the CLT are installed.
       # Expected results:
       # 1. On Xcode-only systems, return the Xcode SDK.

Library/Homebrew/os/mac/xcode.rb

@@ -126,6 +126,7 @@ module OS
 
       sig { returns(T::Boolean) }
       def self.installed?
+        # odeprecated "`MacOS::Xcode.installed?` on Linux" if Homebrew::SimulateSystem.simulating_or_running_on_linux?
         !prefix.nil?
       end
 
@@ -174,6 +175,7 @@ module OS
 
       sig { returns(::Version) }
       def self.version
+        # odeprecated "`MacOS::Xcode.version` on Linux" if Homebrew::SimulateSystem.simulating_or_running_on_linux?
         # may return a version string
         # that is guessed based on the compiler, so do not
         # use it in order to check if Xcode is installed.
@@ -264,6 +266,7 @@ module OS
       # Returns true even if outdated tools are installed.
       sig { returns(T::Boolean) }
       def self.installed?
+        # odeprecated "`MacOS::CLT.installed?` on Linux" if Homebrew::SimulateSystem.simulating_or_running_on_linux?
         !version.null?
       end
 
@@ -397,6 +400,7 @@ module OS
       # version numbers.
       sig { returns(::Version) }
       def self.version
+        # odeprecated "`MacOS::CLT.version` on Linux" if Homebrew::SimulateSystem.simulating_or_running_on_linux?
         if @version ||= detect_version
           ::Version.new @version
         else

Library/Homebrew/readall.rb

@@ -11,6 +11,10 @@ module Readall
   class << self
     include Cachable
 
+    # TODO: remove this once the `MacOS` module is undefined on Linux
+    MACOS_MODULE_REGEX = /\b(MacOS|OS::Mac)(\.|::)\b/.freeze
+    private_constant :MACOS_MODULE_REGEX
+
     private :cache
 
     def valid_ruby_syntax?(ruby_files)
@@ -59,7 +63,9 @@ module Readall
                                                        flags: [], ignore_errors: false)
         readall_formula = readall_formula_class.new(formula_name, file, :stable, tap: tap)
         readall_formula.to_hash
-        cache[:valid_formulae][file] = if readall_formula.on_system_blocks_exist?
+        # TODO: Remove check for MACOS_MODULE_REGEX once the `MacOS` module is undefined on Linux
+        cache[:valid_formulae][file] = if readall_formula.on_system_blocks_exist? ||
+                                          formula_contents.match?(MACOS_MODULE_REGEX)
           [bottle_tag, *cache[:valid_formulae][file]]
         else
           true