$ git clone -n https://src.fedoraproject.org/rpms/rust-rend.git /var/lib/mock/f39-build-1494466-34542/root/chroot_tmpdir/scmroot/rust-rend
Cloning into '/var/lib/mock/f39-build-1494466-34542/root/chroot_tmpdir/scmroot/rust-rend'...
$ git fetch origin 46e637e011d0cf226c7be50efd314e5319eb19c2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-rend
 * [new ref]         46e637e011d0cf226c7be50efd314e5319eb19c2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 46e637e Update to version 0.4.1; Fixes RHBZ#2240492