$ git clone -n https://src.fedoraproject.org/rpms/perl-Number-Fraction.git /var/lib/mock/f45-build-25479-611/root/chroot_tmpdir/scmroot/perl-Number-Fraction
Cloning into '/var/lib/mock/f45-build-25479-611/root/chroot_tmpdir/scmroot/perl-Number-Fraction'...
$ git fetch origin 3a6ee4ee1b5b98961cc05119452dae5a988d7e58:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Number-Fraction
 * [new ref]         3a6ee4ee1b5b98961cc05119452dae5a988d7e58 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3a6ee4e Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild