2018-12-09 02:27:04,696 [INFO] {9250} koji.build.buildroot:487 Running mock as kojibuilder
INFO: mock.py version 1.4.13 starting (python version = 3.7.1)...
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: 1.4.13
INFO: Mock Version: 1.4.13
Start: dnf install
ERROR: Command failed: 
 # /usr/bin/dnf --installroot /var/lib/mock/f30-build-40731-22842/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', ignoring this repo.
Warning: Module or Group 'build' does not exist.
Error: Nothing to do.