Disabled pointer conversion when the relevant macros are unavailable (for Guile 1.8)
diff --git a/Lib/guile/guile_scm_run.swg b/Lib/guile/guile_scm_run.swg
index 52407af..dfe875f 100644
--- a/Lib/guile/guile_scm_run.swg
+++ b/Lib/guile/guile_scm_run.swg
@@ -176,9 +176,11 @@
   if (SCM_NULLP(smob)) {
     *result = NULL;
     return SWIG_OK;
+#if defined(SCM_POINTER_P) && defined(SCM_POINTER_VALUE)
   } else if (SCM_POINTER_P(s)) {
     *result = SCM_POINTER_VALUE(s);
     return SWIG_OK;
+#endif /* if defined(SCM_POINTER_P) && defined(SCM_POINTER_VALUE) */
   } else if (SCM_SMOB_PREDICATE(swig_tag, smob) || SCM_SMOB_PREDICATE(swig_collectable_tag, smob)) {
     /* we do not accept smobs representing destroyed pointers */
     from = (swig_type_info *) SCM_CELL_WORD_2(smob);