Check that /usr/bin/cc exists in `brew doctor`

Refs Homebrew/homebrew#7454.

1 files changed, 7 insertions, 0 deletions

diff --git a/Library/Homebrew/cmd/doctor.rb b/Library/Homebrew/cmd/doctor.rb
index 4e268f630..4f971791c 100644
--- a/Library/Homebrew/cmd/doctor.rb
+++ b/Library/Homebrew/cmd/doctor.rb
@@ -214,6 +214,13 @@ def check_gcc_versions
       EOS
     end
   end
+
+  unless File.exist? '/usr/bin/cc'
+    puts <<-EOS.undent
+      You have no /usr/bin/cc. This will cause numerous build issues. Please
+      reinstall Xcode.
+    EOS
+  end
 end
 
 def __check_subdir_access base