From 9b4a7856ac92e025e9df73ed5d18e4412fa55b5c Mon Sep 17 00:00:00 2001
From: Mike McQuaid <mike@mikemcquaid.com>
Date: Tue, 8 Dec 2020 17:14:00 +0000
Subject: [PATCH 1/2] Revert "RbConfig: fix broken MacOS SDK paths"

This reverts commit 11445e0f3edf29ee64081c5a05b5257d9b5ccdd9.
---
 Library/Homebrew/extend/rbconfig_extension.rb | 17 -----------------
 Library/Homebrew/utils/gems.rb                | 11 -----------
 2 files changed, 28 deletions(-)
 delete mode 100644 Library/Homebrew/extend/rbconfig_extension.rb

diff --git a/Library/Homebrew/extend/rbconfig_extension.rb b/Library/Homebrew/extend/rbconfig_extension.rb
deleted file mode 100644
index e26042eb66e08..0000000000000
--- a/Library/Homebrew/extend/rbconfig_extension.rb
+++ /dev/null
@@ -1,17 +0,0 @@
-# typed: false
-# frozen_string_literal: true
-
-macos_version = ENV["HOMEBREW_MACOS_VERSION"][0..4]
-macos_sdk = "MacOSX#{macos_version}.sdk"
-
-# Ruby hardcodes what might end up being an incorrect SDK path in some of the
-# variables that get used in mkmf.rb.
-# This patches them up to use the correct SDK.
-RbConfig::CONFIG.each do |k, v|
-  next unless v.include?("MacOSX.sdk")
-
-  new_value = v.gsub("MacOSX.sdk", macos_sdk)
-  next unless File.exist?(new_value)
-
-  RbConfig::CONFIG[k] = new_value
-end
diff --git a/Library/Homebrew/utils/gems.rb b/Library/Homebrew/utils/gems.rb
index 3e5c9105500d1..a75f0b8561e06 100644
--- a/Library/Homebrew/utils/gems.rb
+++ b/Library/Homebrew/utils/gems.rb
@@ -109,15 +109,6 @@ def install_bundler_gems!
     install_bundler!
 
     ENV["BUNDLE_GEMFILE"] = File.join(ENV.fetch("HOMEBREW_LIBRARY"), "Homebrew", "Gemfile")
-
-    # We can't use OS.mac? because not enough has
-    # been required yet this early in the boot process
-    if ENV["HOMEBREW_SYSTEM"] == "Macintosh"
-      # This patches up some paths used by mkmf.rb
-      extend_path = File.join(ENV.fetch("HOMEBREW_LIBRARY"), "Homebrew", "extend")
-      ENV["RUBYOPT"] = "-r#{extend_path}/rbconfig_extension"
-    end
-
     @bundle_installed ||= begin
       bundle = File.join(find_in_path("bundle"), "bundle")
       bundle_check_output = `#{bundle} check 2>&1`
@@ -135,8 +126,6 @@ def install_bundler_gems!
       end
     end
 
-    ENV["RUBYOPT"] = ""
-
     setup_gem_environment!
   end
 end

From f7d72ae77cb01b25b77cca9cfb700d3b12d9dbab Mon Sep 17 00:00:00 2001
From: Mike McQuaid <mike@mikemcquaid.com>
Date: Tue, 8 Dec 2020 17:23:06 +0000
Subject: [PATCH 2/2] ruby.sh: don't test ruby on macOS.

Instead defer to the `HOMEBREW_MACOS_SYSTEM_RUBY_NEW_ENOUGH`
variable.
---
 Library/Homebrew/utils/ruby.sh | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Library/Homebrew/utils/ruby.sh b/Library/Homebrew/utils/ruby.sh
index bcd18112018b7..a8ad247e15b50 100644
--- a/Library/Homebrew/utils/ruby.sh
+++ b/Library/Homebrew/utils/ruby.sh
@@ -32,7 +32,8 @@ unusable_ruby() {
   if [[ -n "$HOMEBREW_MACOS_SYSTEM_RUBY_NEW_ENOUGH" ]]
   then
     return 1
-  elif [[ -n "$HOMEBREW_RUBY_PATH" && -z "$HOMEBREW_FORCE_VENDOR_RUBY" ]] && test_ruby "$HOMEBREW_RUBY_PATH"
+  elif [[ -z "$HOMEBREW_MACOS" && -n "$HOMEBREW_RUBY_PATH" && -z "$HOMEBREW_FORCE_VENDOR_RUBY" ]] &&
+       test_ruby "$HOMEBREW_RUBY_PATH"
   then
     return 1
   else