Require Libtool 2.4.6 and Autoconf 2.69.

configure.ac

@@ -4,6 +4,9 @@
 #  autoconf 2.69
 #  libtool  2.4.6
 
+AC_PREREQ([2.69])
+LT_PREREQ([2.4.6])
+
 AC_INIT([cdi], [1.8.3rc], [http://mpimet.mpg.de/cdi])
 
 AC_DEFINE_UNQUOTED(CDI, ["$PACKAGE_VERSION"], [CDI version])

patch/ltmain_sh.patch

 diff --git a/config/ltmain.sh b/config/ltmain.sh
-index 857338f..c19bbcc 100644
+index 0f0a2da..4126a5b 100644
 --- a/config/ltmain.sh
 +++ b/config/ltmain.sh
-@@ -8078,6 +8078,14 @@ func_mode_link ()
+@@ -7859,6 +7859,14 @@ func_mode_link ()
  	# Read the .la file
  	func_source "$lib"