$ git clone -n https://src.fedoraproject.org/rpms/rust-structopt.git /var/lib/mock/f45-build-45227-821/root/chroot_tmpdir/scmroot/rust-structopt
Cloning into '/var/lib/mock/f45-build-45227-821/root/chroot_tmpdir/scmroot/rust-structopt'...
$ git fetch origin 2487bf25c15a8bce56a42662a04ce5da0d3ac705:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-structopt
 * [new ref]         2487bf25c15a8bce56a42662a04ce5da0d3ac705 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2487bf2 Regenerate with rust2rpm v28