diff -up sage-5.12/spkg/build/sage-5.12/module_list.py.orig sage-5.12/spkg/build/sage-5.12/module_list.py
--- sage-5.12/spkg/build/sage-5.12/module_list.py.orig	2013-10-16 12:10:52.183200729 -0300
+++ sage-5.12/spkg/build/sage-5.12/module_list.py	2013-10-16 12:11:01.725201094 -0300
@@ -2109,7 +2109,7 @@ if UNAME[0] == "Darwin" and not UNAME[2]
         )
 
 
-if is_package_installed('lrcalc'):
+if 1:
     ext_modules.append(
         Extension('sage.libs.lrcalc.lrcalc',
                   sources = ["sage/libs/lrcalc/lrcalc.pyx"],