diagnostic: check if Xcode needs CLT installed.

Require the CLT on all but the latest version of macOS to avoid the
continuous workarounds for SDK weirdness.

1 files changed, 10 insertions, 0 deletions

diff --git a/Library/Homebrew/extend/os/mac/diagnostic.rb b/Library/Homebrew/extend/os/mac/diagnostic.rb
index 5c603ca62..f0b923f21 100644
--- a/Library/Homebrew/extend/os/mac/diagnostic.rb
+++ b/Library/Homebrew/extend/os/mac/diagnostic.rb
@@ -19,6 +19,7 @@ module Homebrew
         %w[
           check_xcode_minimum_version
           check_clt_minimum_version
+          check_if_xcode_needs_clt_installed
         ].freeze
       end
 
@@ -124,6 +125,15 @@ module Homebrew
         EOS
       end
 
+      def check_if_xcode_needs_clt_installed
+        return unless MacOS::Xcode.needs_clt_installed?
+
+        <<~EOS
+          Xcode alone is not sufficient on #{MacOS.version.pretty_name}.
+          #{DevelopmentTools.installation_instructions}
+        EOS
+      end
+
       def check_for_osx_gcc_installer
         return unless MacOS.version < "10.7" || ((MacOS::Xcode.version || "0") > "4.1")
         return unless DevelopmentTools.clang_version == "2.1"