$ git clone -n https://src.fedoraproject.org/rpms/rust-cargo.git /var/lib/mock/f41-build-700434-12886/root/chroot_tmpdir/scmroot/rust-cargo
Cloning into '/var/lib/mock/f41-build-700434-12886/root/chroot_tmpdir/scmroot/rust-cargo'...
$ git fetch origin 351490dcafee378a70440b9b7b1d5e5b75169a74:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-cargo
 * [new ref]         351490dcafee378a70440b9b7b1d5e5b75169a74 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 351490d Update to version 0.79.0; Fixes RHBZ#2256108