$ git clone -n https://src.fedoraproject.org/rpms/rust-futures-sink.git /var/lib/mock/f38-build-side-43-rust-devel-1411033-31424/root/chroot_tmpdir/scmroot/rust-futures-sink
Cloning into '/var/lib/mock/f38-build-side-43-rust-devel-1411033-31424/root/chroot_tmpdir/scmroot/rust-futures-sink'...
$ git fetch origin fb28ce9b799308f7e6eede7f5cf174bb933ddb44:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-futures-sink
 * [new ref]         fb28ce9b799308f7e6eede7f5cf174bb933ddb44 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fb28ce9 Update to version 0.3.28; Fixes RHBZ#2183273