diff -Nur guile-1.8.7.orig/libguile/guile-snarf-docs.in guile-1.8.7/libguile/guile-snarf-docs.in
--- guile-1.8.7.orig/libguile/guile-snarf-docs.in 2009-07-03 18:19:00.000000000 -0400
+++ guile-1.8.7/libguile/guile-snarf-docs.in 2009-11-19 12:55:32.487266268 -0500
@@ -23,4 +23,4 @@
 ## Let the user override the preprocessor autoconf found.
 test -n "${CPP+set}" || CPP="@CPP@"

-${CPP} -DSCM_MAGIC_SNARF_DOCS "$@"
+${CPP} -P -DSCM_MAGIC_SNARF_DOCS "$@"