Some M4 macros don't seem to be defined

I am trying reinstall pacman on my Arch Linux distribution. When I run the configure script "configure.ac", I get a bunch of undefined macros: error: possibly undefined macro: AM_INIT_AUTOMAKE. If this token and others are legitimate, please use m4_pattern_allow. See the autoconf documentation. error: possibly undefined macro: AC_PROG_LIBTOOL error: possibly undefined macro: AM_GNU_GETTEXT error: possibly undefined macro: AM_GNU_GETTEXT_VERSION error: possibly undefined macro: AM_CONDITIONAL Does anyone know what would cause these macros to be undefined? Having come from Ubuntu (where everything just works, and is therefore boring), I don't really know about automake.