$ git clone -n https://src.fedoraproject.org/rpms/libart.git /var/lib/mock/f45-build-15845-480/root/chroot_tmpdir/scmroot/libart
Cloning into '/var/lib/mock/f45-build-15845-480/root/chroot_tmpdir/scmroot/libart'...
$ git fetch origin 7df89fc3262b04904e0b99eebcce85f1bd795af2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libart
 * [new ref]         7df89fc3262b04904e0b99eebcce85f1bd795af2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7df89fc Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild