$ git clone -n https://src.fedoraproject.org/rpms/rust-bitstream-io.git /var/lib/mock/f40-build-1221863-22752/root/chroot_tmpdir/scmroot/rust-bitstream-io
Cloning into '/var/lib/mock/f40-build-1221863-22752/root/chroot_tmpdir/scmroot/rust-bitstream-io'...
$ git fetch origin 209e3d0e61a02b7f9612ef43ea308ac87e5ea14c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-bitstream-io
 * [new ref]         209e3d0e61a02b7f9612ef43ea308ac87e5ea14c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 209e3d0 Update to version 2.4.2; Fixes RHBZ#2292426