Update gcc version checks in brew_doctor

brew_doctor's gcc version checks wasn't taking into account the case
where the user doesn't have one or both of GCC 4.0.x and 4.2.x installed.

1 files changed, 12 insertions, 2 deletions

diff --git a/Library/Homebrew/brew_doctor.rb b/Library/Homebrew/brew_doctor.rb
index 37ab588f7..94fbf1e0d 100644
--- a/Library/Homebrew/brew_doctor.rb
+++ b/Library/Homebrew/brew_doctor.rb
@@ -36,7 +36,12 @@ def check_gcc_versions
   gcc_42 = gcc_42_build
   gcc_40 = gcc_40_build
 
-  if gcc_42 < RECOMMENDED_GCC_42
+  if gcc_42 == nil
+    puts <<-EOS.undent
+      We couldn't detect gcc 4.2.x. Some formulas require this compiler.
+
+    EOS
+  elsif gcc_42 < RECOMMENDED_GCC_42
     puts <<-EOS.undent
       Your gcc 4.2.x version is older than the recommended version. It may be advisable
       to upgrade to the latest release of Xcode.
@@ -44,7 +49,12 @@ def check_gcc_versions
     EOS
   end
 
-  if gcc_40 < RECOMMENDED_GCC_40
+  if gcc_40 == nil
+    puts <<-EOS.undent
+      We couldn't detect gcc 4.0.x. Some formulas require this compiler.
+
+    EOS
+  elsif gcc_40 < RECOMMENDED_GCC_40
     puts <<-EOS.undent
       Your gcc 4.0.x version is older than the recommended version. It may be advisable
       to upgrade to the latest release of Xcode.