$ git clone -n https://src.fedoraproject.org/rpms/rust-deltae.git /var/lib/mock/f41-build-side-1-3124862-39482/root/chroot_tmpdir/scmroot/rust-deltae
Cloning into '/var/lib/mock/f41-build-side-1-3124862-39482/root/chroot_tmpdir/scmroot/rust-deltae'...
$ git fetch origin 79bce3152f4ed31a6a65605054c0ca8b51eb8282:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-deltae
 * [new ref]         79bce3152f4ed31a6a65605054c0ca8b51eb8282 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 79bce31 no longer needed