***** aclocal *****
***** PWD: /var/tmp/portage/sys-block/libzbc-5.5.1/work/libzbc-5.5.1
***** aclocal -I m4

/usr/bin/m4:configure.ac:2: Warning: excess arguments to builtin `m4_define' ignored
autom4te-2.70_beta2: error: /usr/bin/m4 failed with exit status: 1
aclocal-1.16: error: echo failed with exit status: 1