$ git clone -n https://src.fedoraproject.org/rpms/rust-ref-cast-impl.git /var/lib/mock/f45-build-44387-813/root/chroot_tmpdir/scmroot/rust-ref-cast-impl
Cloning into '/var/lib/mock/f45-build-44387-813/root/chroot_tmpdir/scmroot/rust-ref-cast-impl'...
$ git fetch origin 690e36cbe9d1feee7ff8e8b9d930f3af9a3d7ac0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-ref-cast-impl
 * [new ref]         690e36cbe9d1feee7ff8e8b9d930f3af9a3d7ac0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 690e36c Update to version 1.0.27; Fixes RHBZ#2502111