Iterating the commit a bit, I think this is how it works without extra

[mmh] / configure.in

diff --git a/configure.in b/configure.in
index c264d6e..d80a2d2 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -14,11 +14,13 @@ dnl define a macro or two
 dnl ---------------------
 
 AC_DEFUN(NMH_PROG_GNU_LIBTOOL, [
+if test -n "$LIBTOOL" ; then
   tmptest=`$LIBTOOL --version 2>&1 | grep GNU`
   if test x"$tmptest" != x  ; then
     GNU_LIBTOOL=1
     AC_SUBST(GNU_LIBTOOL)dnl
   fi
+fi
 ] )