***** aclocal *****
***** PWD: /var/tmp/portage/sys-libs/libmath++-0.0.4/work/libmath++-0.0.4
***** aclocal

aclocal-1.13: warning: autoconf input should be named 'configure.ac', not 'configure.in'
configure.in:22: error: 'AM_CONFIG_HEADER': this macro is obsolete.
    You should use the 'AC_CONFIG_HEADERS' macro instead.
/usr/share/aclocal-1.13/obsolete-err.m4:12: AM_CONFIG_HEADER is expanded from...
configure.in:22: the top level
autom4te-2.69: /usr/bin/m4 failed with exit status: 1
aclocal-1.13: error: echo failed with exit status: 1