$ git clone -n https://src.fedoraproject.org/rpms/libcgroup.git /var/lib/mock/f45-build-16004-481/root/chroot_tmpdir/scmroot/libcgroup
Cloning into '/var/lib/mock/f45-build-16004-481/root/chroot_tmpdir/scmroot/libcgroup'...
$ git fetch origin 6e23825ac585bb8f6b339a08b04687d17b94cb3b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libcgroup
 * [new ref]         6e23825ac585bb8f6b339a08b04687d17b94cb3b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6e23825 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild