$ git clone -n https://src.fedoraproject.org/rpms/libpng15.git /var/lib/mock/f45-build-16926-493/root/chroot_tmpdir/scmroot/libpng15
Cloning into '/var/lib/mock/f45-build-16926-493/root/chroot_tmpdir/scmroot/libpng15'...
$ git fetch origin d89160fb24b40d5bab954b76d6f9be227624714b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libpng15
 * [new ref]         d89160fb24b40d5bab954b76d6f9be227624714b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d89160f Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild