$ git clone -n https://src.fedoraproject.org/rpms/rust-time0.1.git /var/lib/mock/f42-build-side-1-3499891-45966/root/chroot_tmpdir/scmroot/rust-time0.1
Cloning into '/var/lib/mock/f42-build-side-1-3499891-45966/root/chroot_tmpdir/scmroot/rust-time0.1'...
$ git fetch origin 35f9eb4ea048206184c828bdf91298a22ef39c1c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-time0.1
 * [new ref]         35f9eb4ea048206184c828bdf91298a22ef39c1c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 35f9eb4 Drop obsolete rustc-serialize support (deprecated since Rust 1.52)