From 25249f0114a8792de803699c704c7e9e9652f934 Mon Sep 17 00:00:00 2001
From: Mike McQuaid <mike@mikemcquaid.com>
Date: Thu, 20 Sep 2018 13:49:10 +0100
Subject: [PATCH] shims/super/cc: detect High Sierra differently.

Don't rely on `RUBY_PLATFORM`'s kernel version as it's the machine that
Ruby was built on (10.5) for portable ruby.
---
 Library/Homebrew/brew.sh        | 1 +
 Library/Homebrew/shims/scm/git  | 7 +------
 Library/Homebrew/shims/super/cc | 2 +-
 3 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/Library/Homebrew/brew.sh b/Library/Homebrew/brew.sh
index ebea36c38c..942a8ae422 100644
--- a/Library/Homebrew/brew.sh
+++ b/Library/Homebrew/brew.sh
@@ -167,6 +167,7 @@ export HOMEBREW_PROCESSOR
 export HOMEBREW_PRODUCT
 export HOMEBREW_OS_VERSION
 export HOMEBREW_MACOS_VERSION
+export HOMEBREW_MACOS_VERSION_NUMERIC
 export HOMEBREW_USER_AGENT
 export HOMEBREW_USER_AGENT_CURL
 
diff --git a/Library/Homebrew/shims/scm/git b/Library/Homebrew/shims/scm/git
index 7306268fda..0930c0adc3 100755
--- a/Library/Homebrew/shims/scm/git
+++ b/Library/Homebrew/shims/scm/git
@@ -122,12 +122,7 @@ then
   xcode_path="$(/usr/bin/xcode-select -print-path 2>/dev/null)"
   if [[ -z "$xcode_path" ]]
   then
-    if [[ -z "$HOMEBREW_MACOS_VERSION" ]]
-    then
-      HOMEBREW_MACOS_VERSION="$(/usr/bin/sw_vers -productVersion)"
-    fi
-    printf -v macos_version_numeric "%02d%02d%02d" ${HOMEBREW_MACOS_VERSION//./ }
-    if [[ "$macos_version_numeric" -ge "100900" ]]
+    if [[ "$HOMEBREW_MACOS_VERSION_NUMERIC" -ge "100900" ]]
     then
       popup_stub=1
     fi
diff --git a/Library/Homebrew/shims/super/cc b/Library/Homebrew/shims/super/cc
index 0ea2f6e4e9..bbab4c448c 100755
--- a/Library/Homebrew/shims/super/cc
+++ b/Library/Homebrew/shims/super/cc
@@ -18,7 +18,7 @@ def mac?
 end
 
 def high_sierra_or_later?
-  mac? && RUBY_PLATFORM[/darwin\d+/][/\d+/].to_i >= 17
+  mac? && ENV["HOMEBREW_MACOS_VERSION_NUMERIC"].to_s.to_i >= 101300
 end
 
 def linux?