$ git clone -n https://src.fedoraproject.org/rpms/perl-Math-MatrixReal.git /var/lib/mock/f45-build-24716-605/root/chroot_tmpdir/scmroot/perl-Math-MatrixReal
Cloning into '/var/lib/mock/f45-build-24716-605/root/chroot_tmpdir/scmroot/perl-Math-MatrixReal'...
$ git fetch origin d2a52d24de830baceedd59734858769b3d5ffc9b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Math-MatrixReal
 * [new ref]         d2a52d24de830baceedd59734858769b3d5ffc9b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d2a52d2 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild