$ git clone -n https://src.fedoraproject.org/rpms/rubygem-mixlib-shellout.git /var/lib/mock/f45-build-35055-693/root/chroot_tmpdir/scmroot/rubygem-mixlib-shellout
Cloning into '/var/lib/mock/f45-build-35055-693/root/chroot_tmpdir/scmroot/rubygem-mixlib-shellout'...
$ git fetch origin 53790aa5e7b86a76d0a650c05f479761eee55bd3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-mixlib-shellout
 * [new ref]         53790aa5e7b86a76d0a650c05f479761eee55bd3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 53790aa Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild