$ git clone -n https://src.fedoraproject.org/rpms/rust-xml-rs.git /var/lib/mock/f45-build-46222-832/root/chroot_tmpdir/scmroot/rust-xml-rs
Cloning into '/var/lib/mock/f45-build-46222-832/root/chroot_tmpdir/scmroot/rust-xml-rs'...
$ git fetch origin cc2bfde556b710989812bd48f8ef601557305c48:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-xml-rs
 * [new ref]         cc2bfde556b710989812bd48f8ef601557305c48 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cc2bfde Update to version 0.8.29