2018-10-01 13:32:56,467 [INFO] {6758} koji.build.buildroot:440 Running mock as kojibuilder
INFO: mock.py version 1.4.9 starting (python version = 3.6.4)...
Start: init plugins
INFO: selinux disabled
Finish: init plugins
Start: run
Start: clean chroot
Finish: clean chroot
Start: chroot init
INFO: calling preinit hooks
INFO: enabled HW Info plugin
Mock Version: 1.4.9
INFO: Mock Version: 1.4.9
Start: dnf install
ERROR: Command failed: 
 # /usr/bin/dnf --installroot /var/lib/mock/f29-build-30340-16533/root/ --setopt=install_weak_deps=0 groupinstall build
Unable to detect release version (use '--releasever' to specify release version)
Failed to synchronize cache for repo 'build', disabling.
Warning: Module or Group 'build' does not exist.
Error: Nothing to do.