autoconf fails with autoconf-archive v2019.01.06
Running autoreconf in the dbus source tree with autoconf-archive v2019.01.06 installed produces the following error:
***** autoconf *****
***** PWD: /var/tmp/portage/sys-apps/dbus-1.12.12/work/dbus-1.12.12
***** autoconf --force
configure:18977: error: Unexpanded AX_ macro found. Please install GNU autoconf-archive
If this token and others are legitimate, please use m4_pattern_allow.
See the Autoconf documentation.
It looks like it is catching a shell variable named AX_CHECK_GNU_MAKE_HEADLINE from ax_check_gnu_make.m4.
Downstream bug report: https://bugs.gentoo.org/674830