$ git clone -n https://src.fedoraproject.org/rpms/mock-core-configs.git /var/lib/mock/f45-build-19010-539/root/chroot_tmpdir/scmroot/mock-core-configs
Cloning into '/var/lib/mock/f45-build-19010-539/root/chroot_tmpdir/scmroot/mock-core-configs'...
$ git fetch origin 80ecda9b3d2d421608b2b80615083c81d88acbe7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mock-core-configs
 * [new ref]         80ecda9b3d2d421608b2b80615083c81d88acbe7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 80ecda9 Update mock-core-configs to 45.1-1