postgres-xc: cleanup python usage.

Formula/postgres-xc.rb

@@ -76,25 +76,27 @@ class PostgresXc < Formula
   end
 
   def check_python_arch
-    # On 64-bit systems, we need to avoid a 32-bit Framework Python.
-    if python.framework?
-      unless archs_for_command(python.binary).include? :x86_64
-        opoo "Detected a framework Python that does not have 64-bit support in:"
-        puts <<-EOS.undent
-          #{python.prefix}
+    # On 64-bit systems, we need to look for a 32-bit Framework Python.
+    # The configure script prefers this Python version, and if it doesn't
+    # have 64-bit support then linking will fail.
+    framework_python = Pathname.new "/Library/Frameworks/Python.framework/Versions/Current/Python"
+    return unless framework_python.exist?
+    unless (archs_for_command framework_python).include? :x86_64
+      opoo "Detected a framework Python that does not have 64-bit support in:"
+      puts <<-EOS.undent
+        #{framework_python}
 
-          The configure script seems to prefer this version of Python over any others,
-          so you may experience linker problems as described in:
-            http://osdir.com/ml/pgsql-general/2009-09/msg00160.html
+        The configure script seems to prefer this version of Python over any others,
+        so you may experience linker problems as described in:
+          http://osdir.com/ml/pgsql-general/2009-09/msg00160.html
 
-          To fix this issue, you may need to either delete the version of Python
-          shown above, or move it out of the way before brewing PostgreSQL.
+        To fix this issue, you may need to either delete the version of Python
+        shown above, or move it out of the way before brewing PostgreSQL.
 
-          Note that a framework Python in /Library/Frameworks/Python.framework is
-          the "MacPython" version, and not the system-provided version which is in:
-            /System/Library/Frameworks/Python.framework
-        EOS
-      end
+        Note that a framework Python in /Library/Frameworks/Python.framework is
+        the "MacPython" version, and not the system-provided version which is in:
+          /System/Library/Frameworks/Python.framework
+      EOS
     end
   end