$ git clone -n https://src.fedoraproject.org/rpms/rust-ecdsa.git /var/lib/mock/f45-build-41394-782/root/chroot_tmpdir/scmroot/rust-ecdsa
Cloning into '/var/lib/mock/f45-build-41394-782/root/chroot_tmpdir/scmroot/rust-ecdsa'...
$ git fetch origin ef5035dafa50a10d54142b5c83ddf176a272562e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-ecdsa
 * [new ref]         ef5035dafa50a10d54142b5c83ddf176a272562e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ef5035d Update to version 0.17.0; Fixes RHBZ#2496618