Merge pull request #833 from DomT4/death_by_xcode

xcode: die unless Xcode/CLT up-to-date on prerelease macOS

Library/Homebrew/cmd/install.rb

@@ -223,9 +223,16 @@ 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?
+      next if out.nil?
+      if checks.fatal_development_tools_checks.include?(check)
+        odie out
+      else
+        opoo out
+      end
     end
   end
 

Library/Homebrew/diagnostic.rb

@@ -87,12 +87,17 @@ 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?
 

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
@@ -12,6 +12,18 @@ module Homebrew
         ]
       end
 
+      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
         return if ARGV.homebrew_developer?
 
@@ -51,10 +63,17 @@ 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outdated?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           Your Xcode (#{MacOS::Xcode.version}) is outdated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