$ git clone -n https://src.fedoraproject.org/rpms/perl-Math-Spline.git /var/lib/mock/f45-build-24800-606/root/chroot_tmpdir/scmroot/perl-Math-Spline
Cloning into '/var/lib/mock/f45-build-24800-606/root/chroot_tmpdir/scmroot/perl-Math-Spline'...
$ git fetch origin b523afccd4994cf5d58c29cd5c0f1ebfd35b5665:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Math-Spline
 * [new ref]         b523afccd4994cf5d58c29cd5c0f1ebfd35b5665 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b523afc Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild