2018-04-17 08:49:04,418 [INFO] {305} 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: yum install
ERROR: Command failed: 
 # /usr/bin/yum-deprecated --installroot /var/lib/mock/f29-build-1-16/root/ groupinstall build
Yum command has been deprecated, use dnf instead.
See 'man dnf' and 'man yum2dnf' for more information.

There is no installed groups file.
Maybe run: yum groups mark convert (see man yum)
Warning: group build does not exist.
Maybe run: yum groups mark install (see man yum)
Error: No packages in any requested group available to install or update