AM_ICONV

Some third party software, e.g. wavpack, uses AM_ICONV
in its configure.ac when building from git.

(I know we have a port that already comes with ./configure,
so this problem does not occur there.)

I do have automake and the rest installed,
but autogen.sh complains that

autoreconf-2.71: export WARNINGS=
autoreconf-2.71: Entering directory '.'
autoreconf-2.71: configure.ac: not using Gettext
autoreconf-2.71: running: aclocal
configure.ac:66: warning: macro 'AM_ICONV' not found in library

Please excuse my ignorance: I know next to nothing about the auto* hell.
I do have libiconv installed, as well as the following:

autoconf-2.69p3
autoconf-2.71
autoconf-archive-2022.09.03
autogen-5.8.7p7
automake-1.16.5
metaauto-1.0p4

Is there something else I need to have
so that the AM_ICONV macro is recognized,
like the other AM_* stuff in configure.ac?

Thank you,

Jan