$ git clone -n https://src.fedoraproject.org/rpms/rust-subprocess.git /var/lib/mock/f38-build-side-43-rust-devel-1410658-31421/root/chroot_tmpdir/scmroot/rust-subprocess
Cloning into '/var/lib/mock/f38-build-side-43-rust-devel-1410658-31421/root/chroot_tmpdir/scmroot/rust-subprocess'...
$ git fetch origin 654c417b3ef02e5234c976634e889ee0db76b549:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-subprocess
 * [new ref]         654c417b3ef02e5234c976634e889ee0db76b549 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 654c417 Prevent useless test-only binary from being installed