$ git clone -n https://src.fedoraproject.org/rpms/rust-crossbeam-channel.git /var/lib/mock/f40-build-2175853-51067/root/chroot_tmpdir/scmroot/rust-crossbeam-channel
Cloning into '/var/lib/mock/f40-build-2175853-51067/root/chroot_tmpdir/scmroot/rust-crossbeam-channel'...
$ git fetch origin 5704c83ec5251c3eb9bf3dfc7ea873ccacf8d50f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-crossbeam-channel
 * [new ref]         5704c83ec5251c3eb9bf3dfc7ea873ccacf8d50f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5704c83 Update to version 0.5.10; Fixes RHBZ#2254354