Seems like the optional Chroot setup:
"Additional packages to be always present in minimal buildroot"
Stopped working because in the build [1], neither the scl-utils-build nor
compat-rpm-config packages are installed (both should be in installroot
command specified as I have set it to my for f21 chroots).
[1]
http://copr-be.cloud.fedoraproject.org/results/praiskup/autotools/fedora-...
Pavel