$ git clone -n https://src.fedoraproject.org/rpms/rust-ref-cast-impl.git /var/lib/mock/f40-build-2251095-54113/root/chroot_tmpdir/scmroot/rust-ref-cast-impl
Cloning into '/var/lib/mock/f40-build-2251095-54113/root/chroot_tmpdir/scmroot/rust-ref-cast-impl'...
$ git fetch origin f65da2b6c6446a81d8b46699b33f0e70c1d49430:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-ref-cast-impl
 * [new ref]         f65da2b6c6446a81d8b46699b33f0e70c1d49430 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f65da2b Update to version 1.0.22; Fixes RHBZ#2254418