$ git clone -n https://src.fedoraproject.org/rpms/rust-diesel.git /var/lib/mock/f40-build-1070133-19639/root/chroot_tmpdir/scmroot/rust-diesel
Cloning into '/var/lib/mock/f40-build-1070133-19639/root/chroot_tmpdir/scmroot/rust-diesel'...
$ git fetch origin 4512c7b5b0e4c3e413eb5322e53104ea267a7f1e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-diesel
 * [new ref]         4512c7b5b0e4c3e413eb5322e53104ea267a7f1e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4512c7b Update to version 2.1.6; Fixes RHBZ#2269688