diff -up sage-5.9/spkg/build/sage-5.9/c_lib/SConstruct.orig sage-5.9/spkg/build/sage-5.9/c_lib/SConstruct
--- sage-5.9/spkg/build/sage-5.9/c_lib/SConstruct.orig	2013-02-23 12:55:48.382841120 -0300
+++ sage-5.9/spkg/build/sage-5.9/c_lib/SConstruct	2013-02-23 12:56:25.037842523 -0300
@@ -126,18 +126,31 @@ env['PYV']=platform.python_version().rsp
 # The SCons convenience function Split is the only strange thing 
 # to python programmers. It just makes a list by splitting on 
 # whitespace without the syntax clutter of lists of strings.
-includes = ['$SAGE_LOCAL/include/', '$SAGE_LOCAL/include/python$PYV/',
-            '$SAGE_LOCAL/include/NTL/', 'include']
+includes = ['@@includedir@@', '@@includedir@@/python$PYV/',
+            '@@includedir@@/NTL/', 'include']
 cFiles = Split( "convert.c  interrupt.c  memory.c  mpn_pylong.c  mpz_pylong.c") + \
          Split( "mpz_longlong.c stdsage.c  gmp_globals.c" )
 cppFiles = Split( "ZZ_pylong.cpp  ntl_wrap.cpp" )
 srcFiles = cFiles + cppFiles
 
+env.Append(CFLAGS='@@optflags@@')
+env.Append(CXXFLAGS='@@optflags@@')
+env.Append(LINKFLAGS='@@__global_ldflags@@')
+
+libname = "libcsage"
+major = "0"
+shlib_suffix = '.so.' + major
+shlink_flags = [ '@@__global_ldflags@@', '-shared', '-fPIC' ]
+soname = libname + shlib_suffix
+shlink_flags += [ '-Wl,-Bsymbolic', '-Wl,-soname=%s' % soname ]
+
 lib = env.SharedLibrary( "csage", [ "src/" + x for x in srcFiles ],
                          LIBS=['ntl', 'pari', 'gmp', 'python$PYV'], 
-                         LIBPATH=['$SAGE_LOCAL/lib','$SAGE_LOCAL/lib/python$PYV/config/'],
+                         LIBPATH=['@@libdir@@','@@libdir@@/python$PYV/config/'],
+                         SHLIBSUFFIX=shlib_suffix,
+                         SHLINKFLAGS=shlink_flags,
                          CPPPATH=includes )
-env.Install("$SAGE_LOCAL/lib", lib)
+env.Install("@@libdir@@", lib)
 
 #Here we only copy the files over if we are on Cygwin.  Otherwise, the
 #library will be handled by the symlinks created in