1 files changed, 21 insertions, 14 deletions
diff --git a/Library/Homebrew/development_tools.rb b/Library/Homebrew/development_tools.rb
index d081067a8..ea7f5837d 100644
--- a/Library/Homebrew/development_tools.rb
+++ b/Library/Homebrew/development_tools.rb
@@ -42,54 +42,61 @@ class DevelopmentTools
     end
 
     def gcc_40_build_version
-      @gcc_40_build_version ||=
+      @gcc_40_build_version ||= begin
         if (path = locate("gcc-4.0")) &&
            build_version = `#{path} --version 2>/dev/null`[/build (\d{4,})/, 1]
           Version.new build_version
         else
           Version::NULL
         end
+      end
     end
     alias gcc_4_0_build_version gcc_40_build_version
 
     def gcc_42_build_version
-      @gcc_42_build_version ||=
-        begin
-          gcc = locate("gcc-4.2") || HOMEBREW_PREFIX.join("opt/apple-gcc42/bin/gcc-4.2")
-          if gcc.exist? && !gcc.realpath.basename.to_s.start_with?("llvm")&&
-             build_version = `#{gcc} --version 2>/dev/null`[/build (\d{4,})/, 1]
-            Version.new build_version
-          else
-            Version::NULL
-          end
+      @gcc_42_build_version ||= begin
+        gcc = locate("gcc-4.2") || HOMEBREW_PREFIX.join("opt/apple-gcc42/bin/gcc-4.2")
+        if gcc.exist? && !gcc.realpath.basename.to_s.start_with?("llvm")&&
+           build_version = `#{gcc} --version 2>/dev/null`[/build (\d{4,})/, 1]
+          Version.new build_version
+        else
+          Version::NULL
         end
+      end
     end
     alias gcc_build_version gcc_42_build_version
 
     def clang_version
-      @clang_version ||=
+      @clang_version ||= begin
         if (path = locate("clang")) &&
            build_version = `#{path} --version`[/(?:clang|LLVM) version (\d\.\d)/, 1]
           Version.new build_version
         else
           Version::NULL
         end
+      end
     end
 
     def clang_build_version
-      @clang_build_version ||=
+      @clang_build_version ||= begin
         if (path = locate("clang")) &&
            build_version = `#{path} --version`[/clang-(\d{2,})/, 1]
           Version.new build_version
         else
           Version::NULL
         end
+      end
     end
 
     def llvm_clang_build_version
-      @llvm_clang_build_version ||= if Tab.for_name "llvm"
+      @llvm_clang_build_version ||= begin
         path = Formulary.factory("llvm").opt_prefix/"bin/clang"
-        `#{path} --version`[/clang version (\d\.\d\.\d)/, 1]
+        if path.executable? &&
+           build_version = `#{path} --version`[/clang version (\d\.\d\.\d)/, 1]
+          Version.new build_version
+        else
+          Version::NULL
+        end
       end
     end