$ git clone -n https://src.fedoraproject.org/rpms/rust-below-dump.git /var/lib/mock/f38-build-side-43-rust-devel-1399723-31141/root/chroot_tmpdir/scmroot/rust-below-dump
Cloning into '/var/lib/mock/f38-build-side-43-rust-devel-1399723-31141/root/chroot_tmpdir/scmroot/rust-below-dump'...
$ git fetch origin 274528307e94715f1faefef8675c1f9b3454b502:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-below-dump
 * [new ref]         274528307e94715f1faefef8675c1f9b3454b502 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2745283 Update to 0.7.1