By default, these are not used in the normal package, even though they are included in the latest autoconf package. Perhaps a configuration change should be made so that kdevelop will work by default.
You have to export WANT_AUTOCONF_2_5=1 into kdevelop's environment to make it use that version of it. (Or use the kdevelop menu item which should have this builtin). Of course, we could make a wrapper script for kdevelop, etc. But it would be even better to configure kdevelop to export this variable itself, or to use /usr/bin/autoconf-2.53 etc. Is that possible? hm..
If there's anything specific you want me to do, please say so.