$ git clone -n https://src.fedoraproject.org/rpms/perl-Image-Math-Constrain.git /var/lib/mock/f45-build-24304-603/root/chroot_tmpdir/scmroot/perl-Image-Math-Constrain
Cloning into '/var/lib/mock/f45-build-24304-603/root/chroot_tmpdir/scmroot/perl-Image-Math-Constrain'...
$ git fetch origin 2abba6a72300600b269526b2eb0eae2046301590:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Image-Math-Constrain
 * [new ref]         2abba6a72300600b269526b2eb0eae2046301590 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2abba6a Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild