diff '--color=auto' -Nurd libetpan-1.9.4/configure.ac libetpan-1.9.4.new/configure.ac
--- libetpan-1.9.4/configure.ac	2019-11-01 10:58:50.000000000 -0700
+++ libetpan-1.9.4.new/configure.ac	2025-06-21 21:21:07.151176141 -0700
@@ -145,8 +145,7 @@
 
 # Checks for programs.
 AC_LIBTOOL_WIN32_DLL
-LT_AC_PROG_RC
-AC_LIBTOOL_RC
+LT_PROG_RC
 AC_PROG_LIBTOOL
 AC_PROG_MKDIR_P