$ git clone -n https://src.fedoraproject.org/rpms/rust-streaming-iterator.git /var/lib/mock/f42-build-3234186-41196/root/chroot_tmpdir/scmroot/rust-streaming-iterator
Cloning into '/var/lib/mock/f42-build-3234186-41196/root/chroot_tmpdir/scmroot/rust-streaming-iterator'...
$ git fetch origin e791363f70d2a657efdb296db006bc90a1603b5e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-streaming-iterator
 * [new ref]         e791363f70d2a657efdb296db006bc90a1603b5e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e791363 Initial import (rhbz#2338879)