$ git clone -n https://src.fedoraproject.org/rpms/rust-rand_isaac0.4.git /var/lib/mock/f45-build-44250-811/root/chroot_tmpdir/scmroot/rust-rand_isaac0.4
Cloning into '/var/lib/mock/f45-build-44250-811/root/chroot_tmpdir/scmroot/rust-rand_isaac0.4'...
$ git fetch origin 190515df4d79871905e098158116c8bdc270a5d6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-rand_isaac0.4
 * [new ref]         190515df4d79871905e098158116c8bdc270a5d6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 190515d Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild