From 1408b5ffd4dfbac840580ea9946237d8164941d8 Mon Sep 17 00:00:00 2001
From: Dominyk Tiller <dominyktiller@gmail.com>
Date: Tue, 30 Aug 2016 03:54:24 +0100
Subject: [PATCH 1/3] diagnostic: add strict_development_tools_checks

---
 Library/Homebrew/extend/os/mac/diagnostic.rb | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/Library/Homebrew/extend/os/mac/diagnostic.rb b/Library/Homebrew/extend/os/mac/diagnostic.rb
index 120e5d15cf..11d497d608 100644
--- a/Library/Homebrew/extend/os/mac/diagnostic.rb
+++ b/Library/Homebrew/extend/os/mac/diagnostic.rb
@@ -12,6 +12,13 @@ module Homebrew
         ]
       end
 
+      def strict_development_tools_checks
+        %w[
+          check_xcode_up_to_date
+          check_clt_up_to_date
+        ]
+      end
+
       def check_for_unsupported_osx
         return if ARGV.homebrew_developer?
 
@@ -51,10 +58,17 @@ module Homebrew
       def check_xcode_up_to_date
         return unless MacOS::Xcode.installed? && MacOS::Xcode.outdated?
 
+        if OS::Mac.prerelease?
+          xcode_select_nudge = <<-EOS.undent
+            If #{MacOS::Xcode.latest_version} is installed, you may need to:
+              sudo xcode-select --switch /path/to/Xcode-beta.app
+          EOS
+        end
+
         <<-EOS.undent
           Your Xcode (#{MacOS::Xcode.version}) is outdated
           Please update to Xcode #{MacOS::Xcode.latest_version}.
-          #{MacOS::Xcode.update_instructions}
+          #{MacOS::Xcode.update_instructions}#{xcode_select_nudge}
         EOS
       end
 

From 921aa015760a0b85345efd8fb921537499657872 Mon Sep 17 00:00:00 2001
From: Dominyk Tiller <dominyktiller@gmail.com>
Date: Tue, 30 Aug 2016 03:57:07 +0100
Subject: [PATCH 2/3] install: die if Xcode/CLT not up-to-date on prereleases

---
 Library/Homebrew/cmd/install.rb | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Library/Homebrew/cmd/install.rb b/Library/Homebrew/cmd/install.rb
index edf8093bfb..a1df8f459c 100644
--- a/Library/Homebrew/cmd/install.rb
+++ b/Library/Homebrew/cmd/install.rb
@@ -227,6 +227,12 @@ module Homebrew
       out = checks.send(check)
       opoo out unless out.nil?
     end
+    if OS.mac? && MacOS.prerelease?
+      checks.strict_development_tools_checks.each do |strict_check|
+        out = checks.send(strict_check)
+        odie out unless out.nil?
+      end
+    end
   end
 
   def check_macports

From f1cc1265afa43afb9bffba17c9fc18776b62dd99 Mon Sep 17 00:00:00 2001
From: Mike McQuaid <mike@mikemcquaid.com>
Date: Wed, 7 Sep 2016 09:11:06 +0100
Subject: [PATCH 3/3] Refactor MacOS check_development_tools usage.

Better use the abstraction layer so e.g. Linux could have similarly
fatal checks for these things.
---
 Library/Homebrew/cmd/install.rb              | 15 ++++++++-------
 Library/Homebrew/diagnostic.rb               |  7 ++++++-
 Library/Homebrew/extend/os/mac/diagnostic.rb | 17 +++++++++++------
 3 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/Library/Homebrew/cmd/install.rb b/Library/Homebrew/cmd/install.rb
index a1df8f459c..074f5fbc3a 100644
--- a/Library/Homebrew/cmd/install.rb
+++ b/Library/Homebrew/cmd/install.rb
@@ -223,14 +223,15 @@ module Homebrew
 
   def check_development_tools
     checks = Diagnostic::Checks.new
-    checks.all_development_tools_checks.each do |check|
+    all_development_tools_checks = checks.development_tools_checks +
+                                   checks.fatal_development_tools_checks
+    all_development_tools_checks.each do |check|
       out = checks.send(check)
-      opoo out unless out.nil?
-    end
-    if OS.mac? && MacOS.prerelease?
-      checks.strict_development_tools_checks.each do |strict_check|
-        out = checks.send(strict_check)
-        odie out unless out.nil?
+      next if out.nil?
+      if checks.fatal_development_tools_checks.include?(check)
+        odie out
+      else
+        opoo out
       end
     end
   end
diff --git a/Library/Homebrew/diagnostic.rb b/Library/Homebrew/diagnostic.rb
index 7022987f2d..fed971ad77 100644
--- a/Library/Homebrew/diagnostic.rb
+++ b/Library/Homebrew/diagnostic.rb
@@ -86,12 +86,17 @@ module Homebrew
       end
       ############# END HELPERS
 
-      def all_development_tools_checks
+      def development_tools_checks
         %w[
           check_for_installed_developer_tools
         ]
       end
 
+      def fatal_development_tools_checks
+        %w[
+        ]
+      end
+
       def check_for_installed_developer_tools
         return if DevelopmentTools.installed?
 
diff --git a/Library/Homebrew/extend/os/mac/diagnostic.rb b/Library/Homebrew/extend/os/mac/diagnostic.rb
index 11d497d608..27ef71d757 100644
--- a/Library/Homebrew/extend/os/mac/diagnostic.rb
+++ b/Library/Homebrew/extend/os/mac/diagnostic.rb
@@ -1,7 +1,7 @@
 module Homebrew
   module Diagnostic
     class Checks
-      def all_development_tools_checks
+      def development_tools_checks
         %w[
           check_for_unsupported_osx
           check_for_prerelease_xcode
@@ -12,11 +12,16 @@ module Homebrew
         ]
       end
 
-      def strict_development_tools_checks
-        %w[
-          check_xcode_up_to_date
-          check_clt_up_to_date
-        ]
+      def fatal_development_tools_checks
+        if MacOS.prerelease?
+          %w[
+            check_xcode_up_to_date
+            check_clt_up_to_date
+          ]
+        else
+          %w[
+          ]
+        end
       end
 
       def check_for_unsupported_osx