Index: configure.ac
--- configure.ac.orig
+++ configure.ac
@@ -77,7 +77,7 @@ case "${host_os}" in
     GVPLUGIN_VERSION=`expr $GVPLUGIN_CURRENT + 1`
     ;;
   * )
-    GVPLUGIN_VERSION=$GVPLUGIN_CURRENT
+    GVPLUGIN_VERSION=$GVPLUGIN_CURRENT.0
     ;;
 esac
 AC_DEFINE_UNQUOTED(GVPLUGIN_VERSION,$GVPLUGIN_VERSION,[Compatibility version number for plugins.])
@@ -600,7 +600,7 @@ else
       if test "$GUILE_CONFIG" = ""; then
         use_guile="No (guile not available)"
       else
-        [GUILE_VERSION=`$GUILE_CONFIG --version 2>&1 | sed -n '1 s/^.* \+\([0-9\.]\+\)$/\1/ p'`]
+        [GUILE_VERSION=`$GUILE_CONFIG --version 2>&1 | sed -En '1 s/^.* +([0-9\.]+)$/\1/ p'`]
         GUILE_VERSION_MAJOR=`echo $GUILE_VERSION | cut -d '.' -f 1`
         GUILE_VERSION_MINOR=`echo $GUILE_VERSION | cut -d '.' -f 2`
         AC_CHECK_PROGS(GUILE,guile$GUILE_VERSION_MAJOR.$GUILE_VERSION_MINOR guile$GUILE_VERSION_MAJOR guile)
@@ -1760,7 +1760,8 @@ AM_CONDITIONAL([WITH_QT], [test "$use_qt" = "Yes"])
 dnl -----------------------------------
 dnl INCLUDES and LIBS for QUARTZ
 
-if test "${host_os::6}" = "darwin"; then
+# ${host_os::6}": bad substitution
+if test false; then
   AC_ARG_WITH(quartz,
     [AS_HELP_STRING([--with-quartz=yes],[Quartz framework (Mac OS X)])],
     [],[with_quartz=yes])
